CN202652062U - PFC circuit and PFC transformer - Google Patents
PFC circuit and PFC transformer Download PDFInfo
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- CN202652062U CN202652062U CN2012203357905U CN201220335790U CN202652062U CN 202652062 U CN202652062 U CN 202652062U CN 2012203357905 U CN2012203357905 U CN 2012203357905U CN 201220335790 U CN201220335790 U CN 201220335790U CN 202652062 U CN202652062 U CN 202652062U
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- Y02B70/00—Technologies for an efficient end-user side electric power management and consumption
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Abstract
The utility model discloses a PFC circuit and a PFC transformer. The PFC circuit and the PFC transformer are designed to solve problems that output voltage of an existing PFC circuit and a PFC transformer is high, that voltage resistance requirement of each applied component is high so that cost of the circuit is high and economic benefit is poor, etc. The PFC circuit comprises a rectification unit, an inductance, a first controlled switch, a capacitor, a control unit, and a unidirectional conduction pipe. The control unit connected with a positive pole of the capacitor is used to extract a feedback signal and control breakover and disconnection of the first controlled switch. The first controlled switch provides a path for the inductance to release electric energy. When the first controlled switch is conducting, the inductance transforms the electric energy to magnetic field energy and stores the magnetic field energy, and outputs direct voltage. When the first controlled switch is disconnected, the inductance transforms the stored magnetic field energy to the electric energy and releases the electric energy, and the inductance charges the capacitor and outputs direct voltage. The PFC transformer comprises the PFC circuit, and is characterized by simple structure, low cost, convenient use, high power factor, etc.
Description
Technical field
The utility model relates to a kind of pfc circuit and PFC transformer.
Background technology
Turning in the circuit of direct current in interchange is in the process of AC-DC (AC-DC), usually adopt full bridge rectifier that alternating current is carried out rectification and pass through again the high-frequency interchange of electric capacity elimination, for subsequent conditioning circuit (such as the direct current transformation device) provides direct voltage.
At first electric capacity is nonlinear reactance, and the voltage and current that causes inputting in the circuit forms phase difference, reduces power factor (PF);
Secondly, because the full bridge rectifier utilization is the one-way conduction principle of diode, only when the voltage on the electric capacity is lower than input voltage, the conducting of diode, this has just caused the distortion into current waveform, has equally also reduced power factor (PF).
Above-mentioned two reasons cause the harmonic component of power supply circuits many usually, and power factor (PF) is low; Power factor (PF) maintains between 0.5～0.6 usually.
For the interference that reduces electrical network and the pollution of harmonic component, power consumption equipment all can in the civil power input behind full bridge rectifier, carry out the correction of power factor (PF) by PFC (Power Factor Correction) circuit before the transformer usually.
Be illustrated in figure 1 as now common PFC transformer, jointly consisted of by pfc circuit 01 and DC-DC commutator transformer 02.In pfc circuit 01, the rectification circuit VB1 after the civil power input in the rectification unit connects with inductance L 1 and controlled switch V1 and forms loop 1; Simultaneously, diode VD1 and capacitor C 1 are in parallel with controlled switch V1, and electric capacity is in parallel with subsequent conditioning circuit simultaneously, for subsequent conditioning circuit provides direct voltage.When under the control of controlled switch at control device during conducting, in loop 1, form larger electric current after the civil power input, inductance L 1 converts electric energy to magnetic field energy and stores; Because after circuit working was stable, charge accumulation voltage raise in the electric capacity, this moment, capacitance voltage was higher than civil power, and diode VD1 is because the one-way conduction characteristic is in cut-off state, 1 pair of subsequent conditioning circuit continued power of capacitor C this moment.The voltage of electric capacity output is higher than the peak value of high line voltage under the usual condition.Under the universal link input, the highest AC line voltage distribution often reaches 270V, and the direct voltage of electric capacity output should satisfy peak values of ac AC usually
Max* (2)
1/2Condition, so the voltage of capacitor C 1 output is 380V less, usually all be arranged on more than the 400V.
When controlled switch disconnects under control device control because the L1 discharge forms path to capacitor charging with the input voltage stack with VB1-L1-VD1-C1, finally by C1 with output dc voltage value transformer.
The voltage of capacitor C 1 output will be greater than the reason of civil power, inductance L 1 and the stack of civil power at suffered voltage of C1 charging stage, at high-frequency control device control line, the charging of C1 intermittent, finally can form C1 voltage greater than civil power and satisfy the circuit design requirement, form the high voltage direct current of output.
Power factor (PF) PF=effective power/apparent power=V
I* I
I* COSA/V
I* I
Rms=I
I* COSA/I
Rms, wherein, V
IEffective voltage, I
IBe effective current, I
RmsBe fundamental current, A be in input voltage and the loop electric current phase difference, what the power factor (PF) adjustment was large is achieved as follows:
A, control device connect the circuit that obtains the electric capacity two ends by circuit and form feedback;
B, control device are according to the multiple calculating of feedback by PFC analysis comparison model, and conducting and the closure of control switch pipe V1 make input current follow input voltage, and phase difference is zero, and COSA=1 makes I simultaneously
RmsFor sinusoidal electric with the stream harmonic carcellation, so that I
I/ I
Rms=1, thus reach the purpose of Active PFC.
Said structure is the PFC booster circuit, and technology is quite ripe, and power factor (PF) can reach 0.99 after revising, but has the following disadvantages simultaneously:
1, because the direct voltage of the output of PFC booster circuit reaches 400V, require the electric capacity voltage endurance capability strong, and the above voltage of 400V must be able to be provided, the capacitance selection face is narrower, and the strong electric capacity cost height of resistance to pressure.
2, the direct voltage of simultaneously capacitor C 1 output provides voltage for follow-up device, voltage is up to 400V, so require the device in the subsequent conditioning circuit to have equally very strong withstand voltage properties, V2 as shown in fig. 1, V3, C2 and T1 all need the device that adopts voltage stress higher, and cost is high.
The utility model content
For the problems referred to above, the utility model provides a kind of pfc circuit and the PFC transformer low, with low cost to each electricity consumption component pressure performance requirement.
For reaching above-mentioned purpose, the utility model pfc circuit comprises:
Rectification unit is by two inputs, rectification module and two outputs of exporting commutating voltages of the input AC electricity of connection form successively;
Be connected on the first controlled switch, inductance and the electric capacity of described rectification unit two outputs;
Control unit is electrically connected with the positive pole of described electric capacity, extracts feedback signal, draws the control signal that can improve power factor (PF) in order to analyze comparison model according to feedback signal and built-in PFC, thereby controls conducting and the disconnection of described the first controlled switch;
The one-way conduction element, forming releasing of one-way conduction with described inductance and described capacitances in series can the loop;
Wherein, when described the first controlled switch conducting, described rectification unit and described inductance and described capacitances in series form tank circuit, described one-way conduction element cut-off, described inductance is with the electric energy conversion and save as magnetic field energy, and described electric capacity is removed the high fdrequency component in the input current;
When described the first controlled switch disconnects, described rectification unit open circuit, described one-way conduction element conductive, described inductance is converted to electric energy with the magnetic field energy that stores, and to described capacitor charging, the while is output dc voltage externally by described one-way conduction element.
Preferably, described control unit comprises that the feedback detection sub-unit, the PFC that connect successively analyze relatively subelement and control level output subelement;
Described feedback detection sub-unit one end is connected to the positive pole of described electric capacity, according to the Voltage-output feedback signal of described electric capacity output;
Described PFC analyzes relatively subelement, receives the feedback signal of described feedback detection sub-unit output, and analyzes comparison model according to the feedback signal that receives and built-in PFC, generates and the output drive control signal;
Described control level output subelement receives described drive control signal and generates described control signal; Wherein said control signal is control level; Described controlled switch conducting when described control level is high level, described controlled switch disconnects when described control level is low level.
Preferably, described feedback detection sub-unit comprises resistance R 5, R6, low-voltage dc power supply, thyristor and optical coupler; Described resistance R 5 is connected with R6 afterwards and described Capacitance parallel connection; The A utmost point of described thyristor and the G utmost point are connected to described resistance R 6 two ends; The K utmost point of described thyristor links to each other with described low-voltage dc power supply is anodal; The luminous component of described optical coupler is connected in the loop that is formed by described low-voltage dc power supply and Thyristors in series; The light accepting part of described optical coupler divides with described PFC analysis comparison subelement and links to each other;
When the voltage of described electric capacity surpasses rated voltage, the conducting of described thyristor, the light accepting part of described optical coupler divides the light signal output current luminous according to its luminous component; Described output current is described feedback signal.
Preferably, described feedback detection sub-unit comprises that one is used for the current sensor according to described electric capacity both end voltage output current; The output current of described current sensor is input to described PFC and analyzes relatively subelement; Described PFC analyzes and compares subelement according to the electric current generation drive control signal of described current sensor output.
Preferably, described control level output subelement is PWM level output device, and when described control level was low level, the magnitude of voltage of output was zero; Described PWM level output device is adjusted the duty ratio of control level according to described drive control signal.
Preferably, be in series with a fuse on described rectification unit two inputs or two outputs;
Described pfc circuit also comprises the short-circuit protection circuit that is connected in parallel on described electric capacity two ends; when causing the voltage at described electric capacity two ends, the unusually lasting conducting of described controlled switch surpasses rated voltage; then described short-circuit protection circuit conducting is connected with two outputs of described rectification unit and is formed Low ESR conducting loop, produces large electric current and causes described blown fuse.
Preferably, described short-circuit protection circuit is divided into conducting control sub-loop and sub-series loop;
Described conducting control sub-loop comprises a voltage comparison module,
Described sub-series loop is second controlled switch that is connected in parallel on described electric capacity two ends;
Described voltage comparison module first input end is connected to the positive pole of described electric capacity, predeterminated voltage of the second input input;
When the magnitude of voltage of the output of described electric capacity during greater than described predeterminated voltage, forward voltage of described voltage comparison module output is given described the second controlled switch, described the second controlled switch conducting;
When the magnitude of voltage of the output of described electric capacity was equal to or less than described predeterminated voltage, negative voltage of described voltage comparison module output was given described the second controlled switch, and described the second controlled switch disconnects so that described sub-series loop disconnects.
Preferably, described the first controlled switch can be triode or MOSET pipe;
The emitter and collector of described triode is connected on described tank circuit and described releasing in the energy loop, and the base stage of described triode is connected in the described control loop;
The drain electrode of described MOSET and source series are described tank circuit and described releasing in the energy loop, and the gate pole of described MOSET is connected in the described control loop.
Preferably, described the first controlled switch is connected on the rear end of described inductance and described electric capacity, links to each other with the negative pole of the output of described rectification unit.
For reaching above-mentioned purpose, the utility model PFC transformer, just comprise alternating current input module, pfc circuit module and DC-DC voltage changing module, it is characterized in that, described pfc circuit module is above-mentioned pfc circuit, described alternating current input module receives the civil power input, for described pfc circuit provides alternating voltage; Described pfc circuit provides the direct voltage of input for described DC-DC voltage changing module.
The beneficial effect of the utility model pfc circuit and PFC transformer:
1, the utility model pfc circuit and PFC transformer, changed the situation that traditional pfc circuit and PFC transformer adopting booster circuit realize that power factor (PF) is adjusted, control signal by control unit output bring to power factor, control conducting and the disconnection of the first controlled switch, equally can the bring to power factor, reduce electrical network the power consumption equipment that includes pfc circuit or PFC transformer is disturbed and harmonic pollution.
2, the utility model pfc circuit and PFC transformer adopt the buck topology structure, during the tank circuit conducting, and inductance and capacitances in series dividing potential drop, the voltage of electric capacity output is lower than the alternating voltage of input; Disconnecting at tank circuit can the loop during conducting by releasing, and inductance and electric capacity are jointly for subsequent conditioning circuit provides electric energy, and output voltage still is lower than input voltage.So the withstand voltage properties to electric capacity and subsequent conditioning circuit element (such as the DC-DC voltage changing module in the PFC transformer---in the direct current transformation module use electric device) requires to reduce, so cost of each element, low, good in economic efficiency with respect to traditional pfc circuit and PFC transformer cost.
3, the utility model pfc circuit and PFC transformer, adopt the buck topology structure, the direct voltage of output can be controlled in about 80V, the direct voltage of exporting in traditional pfc circuit and the PFC transformer is 400V, so that the Transformer Winding number of turn in the follow-up DC-DC voltage changing module reduces, thereby the volume of transformer reduces, when described pfc circuit and PFC transformer application in the electric supply installation at power consumption equipment the time, further dwindled the volume of electric supply installation, when having reduced the electric supply installation cost, improved the competitiveness of this power consumption equipment and like product.
4, the utility model pfc circuit and PFC transformer; adopt short-circuit protection circuit; when the controlled switch in pfc circuit or the PFC transformer unusually during lasting conducting; short-circuit protection circuit will form Low ESR conducting loop with rectification unit; produce large electric current and cause blown fuse in the described rectification circuit; thereby interruption of power supply, other original paper in protection power consumption equipment and the supply network.
5, the utility model pfc circuit and PFC transformer adopt short-circuit protection circuit, avoided electric capacity breakdown cause fire risk, be applied in the security performance that can improve power consumption equipment and power utilization network in power consumption equipment or the power utilization network.
6, the utility model pfc circuit and PFC transformer, link to each other with the negative pole of rectification unit after the first controlled switch in the tank circuit arranged inductance and electric capacity, the voltage that the first controlled switch connects is lower, like this control unit can by a less voltage just can be easy realization to the control of the first controlled switch pipe, control easy.
7, the utility model pfc circuit and PFC transformer, simple in structure, applied range, can be applicable in the direct-flow electricity utilization apparatus of relatively high power, broken the situation that in the past traditional boost type pfc circuit and boost type PFC transformer monopolization Active PFC are used, more more excellent application choices are provided.
Description of drawings
Fig. 1 is traditional boost type PFC transformer;
Fig. 2 A is structural representation described in the utility model pfc circuit embodiment one, embodiment two, embodiment three, embodiment four and the embodiment five;
Fig. 2 B is the equivalent circuit diagram of the controlled switch conducting of the described pfc circuit of Fig. 1;
Fig. 2 C is the equivalent circuit diagram that the controlled switch of the described pfc circuit of Fig. 1 disconnects;
Fig. 3 is the structural representation of control unit described in the utility model pfc circuit embodiment three;
Fig. 4 is feedback detection sub-unit structural representation among the utility model pfc circuit embodiment four;
Fig. 5 is feedback detection sub-unit structural representation among the utility model pfc circuit embodiment five;
Fig. 6 is the pfc circuit structural representation described in the utility model embodiment six;
Fig. 7 is structural representation described in the real PFC transformer of the utility model embodiment eight.
Embodiment
Below in conjunction with Figure of description the utility model is further described.
Embodiment one:
Shown in Fig. 2 A, the present embodiment pfc circuit comprises:
Rectification unit is in order to carry out rectification to input voltage and input current; Rectification unit adopts the diode full-bridge rectification,
Be connected on first controlled switch, inductance L 1 of described rectification circuit two outputs ' and capacitor C 1 ';
Control unit is electrically connected with the positive pole of described electric capacity, extracts feedback signal, draws the control signal that can improve power factor (PF) in order to analyze comparison model according to feedback signal and built-in PFC, thereby controls conducting and the disconnection of described controlled switch; Described PFC analysis comparison model can be continued to use the system model in traditional boost type pfc circuit;
One-way conduction element with described inductance L 1 ' and described capacitor C 1 ' connect; The one-way conduction element that adopts in the present embodiment is diode VD1 ';
Wherein, when described the first controlled switch conducting, described rectification unit is connected with described tank circuit and is formed path, so the voltage of described one-way conduction component of diode VD1 ' forward conduction end is in cut-off state less than the voltage that oppositely ends end, this moment, circuit equivalent was in the circuit shown in Fig. 2 B; Described inductance L 1 ' magnetic field energy, the high fdrequency component in described capacitor C 1 ' removal input current are changed and saved as to electric energy; The size of the direct voltage of output equals the voltage swing at capacitor C 1 ' two ends; This moment inductance L 1 ' be connected in series with capacitor C 1 ' belong to, the voltage sum of two elements equals the size of input voltage, if input is that the magnitude of voltage then exported of civil power is less than the civil power peak value, inductance L 1 ' with respect to capacitor C 1 ' voltage played the effect of a dividing potential drop step-down, usually the size of capacitor C 1 ' both end voltage value can require to arrange according to power consumption equipment, controlled switch closes after the repeatedly conducting disconnection, the voltage at capacitor C 1 ' two ends is less than or equal to rated voltage and tend towards stability, thus output be one less than the direct voltage of input civil power peak value;
When described the first controlled switch disconnects, described rectification unit and described tank circuit all disconnect, the described inductance L 1 ' magnetic field energy that stores is converted to electric energy and release, VD1 ' the conducting of described individual event breakover element diode, described inductance L 1 ' to described capacitor C 1 ' charging, simultaneously external output dc voltage, the circuit structure of this moment is equivalent to shown in Fig. 2 C, controlled switch disconnects under the control of control unit, is under the open-circuit condition with respect to rectification unit.In order to guarantee that to the back-end load or DC-DC transformer provide uninterruptable power output, this moment, inductance L 1 ' converting the magnetic field energy of its storage to electric energy rang capacitor C 1 ' charging by diode VD1, keep the voltage at capacitor C 1 ' two ends constant, simultaneously outside output dc voltage, the size of direct voltage equals the size of the voltage at capacitor C 1 ' two ends.
The boost type pfc circuit that the described pfc circuit of present embodiment is relatively traditional or boost type PFC transformer, in the situation that the components and parts kind is not changed, change the annexation of each components and parts, thereby can with the step-down mode realize power factor (PF) lifting, simple in structure, require low to the withstand voltage properties of each components and parts, cost is low, and is good in economic efficiency.
The lifting of power factor (PF) comprises two aspects: the one, and by adjusting the phase difference between input voltage and the input current, phase difference is less, and power factor (PF) is higher; The 2nd, the harmonic component of reduction input current makes input current present sine wave as far as possible.PFC analyzes comparison model and makes input current follow the input voltage variation to reach and dwindle phase difference by analyzing the calculating that relatively waits multi-step, making simultaneously input current be sinusoidal wave shape can disturb by harmonic carcellation, thereby the bring to power factor reduces the interference of electrical network and the pollution of harmonic component.
Embodiment two:
Shown in Fig. 2 A, on the basis of embodiment one, described the first controlled switch of present embodiment is operated under the electric current discontinuous mode; Usually the mode of operation of the controlled switch in booster circuit or the reduction voltage circuit has two kinds under the state.
The time that described the first controlled switch, conducting once continue is turn-on cycle; Disconnecting the time that once continues is break period, switch periods of the common formation of adjacent turn-on cycle and break period; When inductance under the effect of the first controlled switch, discharge in the break period is until electric current drops to zero, the electric current of the inductance of flowing through in turn-on cycle then claims described controlled switch to be operated under the discontinuous mode from the peak value that is raised to above freezing; As the first controlled switch in a switch periods, do not have electric current be zero point then the first controlled switch be operated under the continuous current mode.
Can both play the effect that power factor (PF) is regulated under two kinds of mode of operations, but power greater than 300 watts power consumption equipment in the general electric current discontinuous mode that adopts.
Described the first controlled switch can be triode, control unit loads a high level between the base stage of triode and the collector electrode, when described high level during greater than the deflecting voltage of triode, and conducting between the emitter and collector of triode, the tank circuit conducting, inductance L 1 ' energy storage.When control unit loads a low level between the base stage of triode and the collector electrode, when described low level is zero or during less than the deflecting voltage of triode, be equivalent to open circuit between the emitter and collector of triode, the tank circuit cut-off is released and can be released energy by the one-way conduction element by loop conducting inductance L1 '.
Described the first controlled switch can be the MOSET pipe, control unit loads a high level between the gate pole of MOSET pipe and the source electrode, when described high level during greater than the deflecting voltage of MOSET pipe, and conducting between the drain electrode of MOSET pipe and the source electrode, the tank circuit conducting, inductance L 1 ' energy storage.When control unit loads a low level between the gate pole of MOSET pipe and the source electrode, when described low level is zero or during less than the deflecting voltage of MOSET pipe, be equivalent to open circuit between the drain electrode of MOSET pipe and the source electrode, the tank circuit cut-off is released and can be released energy by the one-way conduction element by loop conducting inductance L1 '.The preferred MOSET pipe of this enforcement pfc circuit.
Embodiment three:
Such as Fig. 2 A, Fig. 2 B, Fig. 2 C and shown in Figure 3, the present embodiment pfc circuit comprises:
Rectification unit adopts the diode full-bridge rectification, comprises the output of input, rectification module and the two output commutating voltages of two input AC points
Be connected on the first controlled switch between described rectification circuit two outputs, inductance L 1 ' and capacitor C 1 ';
Comprise control unit, be electrically connected with the positive pole of described electric capacity, extract feedback signal, draw the control signal that can improve power factor (PF) in order to analyze comparison model according to feedback signal and built-in PFC, thereby control conducting and the disconnection of described the first controlled switch; Described PFC analysis comparison model can be continued to use the system model in traditional boost type pfc circuit, can realize the various functions that present embodiment is required;
Releasing can the loop, comprise the described inductance L 1 of mutual series connection ', described capacitor C 1 ' and one-way conduction element; The one-way conduction element that adopts in the present embodiment is diode VD1 ';
Wherein, when described the first controlled switch conducting, described rectification unit and described inductance L 1 ' and capacitor C 1 ' connecting forms tank circuit, so the voltage of described one-way conduction component of diode VD1 ' forward conduction end is in cut-off state less than the voltage that oppositely ends end, this moment, circuit equivalent was in the circuit shown in Fig. 2 B; Described inductance L 1 ' magnetic field energy, the high fdrequency component in described capacitor C 1 ' removal input current are changed and saved as to electric energy; The size of the direct voltage of output equals the voltage swing at capacitor C 1 ' two ends; When described the first controlled switch disconnects, described rectification unit and described inductance L 1 ' and described capacitor C 1 ' all disconnect, the described inductance L 1 ' magnetic field energy that stores is converted to electric energy and release, VD1 ' the conducting of described individual event breakover element diode, described inductance L 1 ' to described capacitor C 1 ' charging, simultaneously external output dc voltage, the circuit structure of this moment is equivalent to shown in Fig. 2 C, controlled switch disconnects under the control of control unit, is under the open-circuit condition with respect to rectification unit.
Control unit in the described control loop is divided into again 3 subelements and analyzes relatively subelement and control level subelement for feedback detection sub-unit, the PFC that connects successively. and described PFC analysis relatively subelement has comprised that described PFC analyzes comparison model.Feedback detection sub-unit one end be connected to capacitor C 1 ' positive pole, one end is connected to PFC and analyzes the relatively discrepancy end of subelement, with its from capacitor C 1 ' the feedback voltage of extraction generate PFC and analyze the signal of telecommunication that subelement relatively can identify, and the described signal of telecommunication be input to described PFC analysis compare subelement.Described PFC analyzes and draws drive control signal after subelement relatively compares the multiple computings such as computing, multiplying according to the numerical value of the signal of telecommunication that receives and its internal preset, output to described control level subelement, export control signal by the control level subelement according to drive control signal, described control signal is control level, because the control controlled switch is such as two kinds of described triodes of embodiment or MOSET pipe.
Described control loop adopts three subelements both can realize function to the circuit step-down, simultaneously also easy realization the function of Modulating Power factor PF (Power Factor) size.
Embodiment four:
In the feedback detection sub-unit described in the embodiment three multiple implementation structure is arranged, such as Fig. 2 A and shown in Figure 4, present embodiment has been specialized the feedback detection sub-unit on the basis of embodiment three.Described feedback detection sub-unit comprises resistance R 5, R6, low-voltage dc power supply Vdd, thyristor and the optical coupler N2 of two series connection; Described resistance R 5, R6 and described capacitor C 1 ' in parallel; 1 two inputs of the A utmost point 2 of described thyristor N3 and the G utmost point are connected in parallel on resistance R 6 two ends; The K utmost point 3 of described thyristor is connected on the pin 2 of luminous component of optical coupler N2, and is connected on the low-voltage dc power supply Vdd by the pin 1 of optical coupler N2; The luminous component of described optical coupler N2 is connected in the loop that is formed by described low-voltage dc power supply and Thyristors in series, when the voltage at the A utmost point among the thyristor N3 2 and the G utmost point 1 two ends greater than 0 the time, described thyristor N2 conducting, then the section that gives out light of described optical coupler N2 is luminous, and the light accepting part by optical coupler N2 is input to relatively subelement of described PFC analysis with the feedback signal of producing again; When the voltage at the A utmost point in the thyristor 2 and the G utmost point 1 two ends less than 0 the time, thyristor N3 disconnects, the illuminating part of optical coupler N2 presents dark state, the light accepting part of optical coupler N2 is exported without feedback signal FB.In break period, when the voltage of capacitor C 1 ' output acts on series resistance R5 and the resistance R 6, the voltage that R6 divides is during less than the predeterminated voltage of the thyristor G utmost point, illustrate that inductive discharge is complete at this moment, the voltage drop of electric capacity has arrived minimum, need to be to the described controlled switch of conducting, to inductance and capacitor charging, and controlled switch ON time can be in each input voltage change in voltage fixed value in the cycle after rectification, then controlled switch disconnection that time is up, when the voltage drop of electric capacity is following to minimum or minimum, then controlled switch conducting.
The present embodiment pfc circuit adopts the original papers such as optical coupler and thyristor to realize extraction to the feedback signal of pfc circuit, and is simple in structure, the result is accurate.
Embodiment five:
In the feedback detection sub-unit described in the embodiment three multiple implementation structure is arranged, such as Fig. 2 A and shown in Figure 4, present embodiment has been specialized the feedback detection sub-unit on the basis of embodiment three.Described feedback detection sub-unit comprises that one is used for the current sensor N4 according to described electric capacity both end voltage output current; The output current of described current sensor is input to described PFC and analyzes relatively subelement; Described PFC analyzes and compares subelement according to the electric current generation drive control signal of described current sensor output.
Described control level output subelement is PWM (pulse modulation) level output device, and when described control level was low level, the magnitude of voltage of output was zero; Described PWM level output device is adjusted the duty ratio of control level according to described drive control signal.When controlled switch was triode or MOSET pipe, control unit can be by conducting and the disconnection of adjustment to the height control tank circuit of the level of controlled switch input.As long as the voltage of control level output subelement output gets final product conducting greater than the bias voltage may of triode or MOSET pipe, otherwise disconnects.Can be random and in turn-on cycle, satisfy the wave form varies of voltage greater than bias voltage may the time, it also can be voltage arbitrary value or the reverse voltage that is lower than bias voltage may that voltage can be arranged in break period, the variation of waveform is also random.And the described control level output of present embodiment subelement adopts PWM level output device, and the square-wave voltage after modulation of output is recently realized conducting and the disconnection of controlled switch by controlling duty, and realization is simple, adjusts accurately.
Embodiment six:
As shown in Figure 6, present embodiment is a kind of distortion of embodiment one described pfc circuit.With respect to embodiment one, present embodiment, with the first controlled switch in the tank circuit be arranged on described inductance L 1 ' and described capacitor C 1 ' the rear end, link to each other with the low-voltage output of described rectification unit.
Be arranged so that like this voltage that described the first controlled switch is connected to the tank circuit two ends is lower, when control unit is realized control by high-low level to it, only need less voltage of input just can realize controlling, control easier.
Embodiment seven:
Shown in Figure 7 is that wherein label 1,2 and 3 circuit that form are pfc circuit described in the present embodiment to one of the utility model PFC transformer device structure schematic diagram.
The present embodiment pfc circuit comprises:
Be connected on the first controlled switch, inductance and the electric capacity of described rectification circuit two commutating voltage outputs, when described the first controlled switch conducting, form tank circuit,
Comprise control unit, be electrically connected with the positive pole of described electric capacity, extract feedback signal, draw the control signal that can improve power factor (PF) in order to analyze comparison model according to feedback signal and built-in PFC, thereby control conducting and the disconnection of described controlled switch;
One-way conduction unit forms with described inductance and described capacitances in series and releases energy loop 3,
Wherein, when described the first controlled switch conducting, described rectification unit is connected with described tank circuit and is formed path, described one-way conduction element cut-off, and described inductance is with the electric energy conversion and save as magnetic field energy, and described electric capacity is removed the high fdrequency component in the input current;
The output of described rectification unit or input also comprise a fuse;
When described the first controlled switch disconnects, described rectification unit and described tank circuit all disconnect, and described inductance is converted to the magnetic field energy that stores electric energy and discharges the conducting of described individual event breakover element, described inductance is to described capacitor charging, and the while is output dc voltage externally.
Short-circuit protection circuit; when causing the voltage at described electric capacity two ends, the unusually lasting conducting of described the first controlled switch surpasses rated voltage; then described short-circuit protection circuit conducting is connected with described rectification circuit and is formed Low ESR conducting loop, produces large electric current and causes the fuse FUSE in the described rectification circuit to fuse.
Wherein label 2 represents the circuit that step-down in the pfc circuit and power factor (PF) adjust and consists of, and label 1 then is that the circuit that input voltage vin is carried out rectification is consisted of.
When the unusually lasting conducting of the first controlled switch occurring; as shown in Figure 7 drain electrode 2 and source electrode 3 short circuits of MOSET pipe V1; then capacitor C 1 will continue cumulative voltage; voltage is the most breakdown with overrate; because puncturing moment will give off sparks; this type of phenomenon will be mortal wound in power consumption equipment, in use may cause the electricity consumption disaster, evade this type of phenomenon so designed short-circuit protection circuit in the present embodiment.
Present embodiment also provides a kind of short-circuit protection circuit concrete structure in addition, as shown in the reference numeral 3.
Short-circuit protection circuit is divided into conducting control sub-loop and sub-series loop; Described conducting control sub-loop comprises a voltage comparison module, described voltage comparison module is shown in label among Fig. 73, comprise a comparator V4, described sub-series loop is second controlled switch that is connected in parallel on described electric capacity two ends, and described the second controlled switch is thyristor VS1; Described comparator V4 first input end is connected to the positive pole of described capacitor C 1, predeterminated voltage of the second input input; Described predeterminated voltage is resistance R 2 both end voltage values, because Vdd1 is the dc constant voltage source, and after resistance R 1 and resistance R 2 dividing potential drops, the voltage stabilization at R2 two ends, and what be connected in parallel on electric capacity two ends inputs is that the R3 of PFC-Vout voltage and the voltage at R4 two ends are directly proportional with PFC-Vout voltage, with the voltage ratio at predeterminated voltage and R4 two ends, the level value after one of the output of the pin one by V2 relatively again, when output is the high level conducting, rectification unit and the conducting of sub-series loop during thyristor VS1 conducting, namely form low-impedance path through VS1, export large electric current, this moment is when satisfying thyristor I
2T is greater than fuse I
2T just can fuse FUSE, causes the open circuit of whole circuit.Thyristor VS1 is described controlled switch.
After forming large electric current at thyristor VS1, input current increases thereupon, and the fusing of FUSE will appear in the sign that can carry of over insurance silk, forms open circuit, and the prevention accident occurs.
Described thyristor also can replace with triode or MOSET pipe belt.
Embodiment eight:
As shown in Figure 7, present embodiment PFC transformer, just comprise alternating current input module, pfc circuit module and DC-DC voltage changing module, any states pfc circuit among the described pfc circuit module embodiment one to embodiment six, described alternating current input module receives the civil power input, for described pfc circuit provides alternating voltage; Described pfc circuit provides the direct voltage of input for described DC-DC voltage changing module.
In the present embodiment, alternating current is through behind the described alternating current input module, having become after rectification unit 1 rectification via the pfc circuit module and become periodically variable direct voltage, is tank circuit and to release after can loop step-down Modulating Power factor be that galvanic current is pressed from the output of capacitor C 1 two ends via the circuit of label 2 representatives.4 the representative be described DC-DC direct current transformation module comprising commutator transformer T1, and control transformer ratio hemisphere control unit and controlled switch V2 and V3.Present embodiment PFC transformer adopting PFC transforming circuit described in the utility model, PFC-Vout voltage can be arranged on about 80V, greatly reduces with respect to the voltage of 400V in the traditional structure.So the umber of turn of transformer T1 also can reduce greatly, thereby reduced the volume of PFC transformer, when being assembled into such as LCD TV, in the time of in plasm TV, refrigerator, the air-conditioning large electric appliances, the space that takies is less, and layout is more flexible, particularly existing LCD TV development trend is for more and more thinner, components and parts to its inside also propose volume requirement, should be more compatible stronger, and the competitiveness of product is stronger.
More than; it only is preferred embodiment of the present utility model; but protection range of the present utility model is not limited to this; anyly be familiar with those skilled in the art in the technical scope that the utility model discloses; the variation that can expect easily or replacement all should be encompassed within the protection range of the present utility model.Therefore, protection range of the present utility model should be as the criterion with the protection range that claim was defined.
Claims (10)
1. a pfc circuit is characterized in that, described pfc circuit comprises:
Rectification unit is by two inputs, rectification module and two outputs of exporting commutating voltages of the input AC electricity of connection form successively;
Be connected on the first controlled switch, inductance and the electric capacity of described rectification unit two outputs;
Control unit is electrically connected with the positive pole of described electric capacity, extracts feedback signal, draws the control signal that can improve power factor (PF) in order to analyze comparison model according to feedback signal and built-in PFC, thereby controls conducting and the disconnection of described the first controlled switch;
The one-way conduction element, forming releasing of one-way conduction with described inductance and described capacitances in series can the loop;
Wherein, when described the first controlled switch conducting, described rectification unit and described inductance and described capacitances in series form tank circuit, described one-way conduction element cut-off, described inductance is with the electric energy conversion and save as magnetic field energy, and described electric capacity is removed the high fdrequency component in the input current;
When described the first controlled switch disconnects, described rectification unit open circuit, described one-way conduction element conductive, described inductance is converted to electric energy with the magnetic field energy that stores, and to described capacitor charging, the while is output dc voltage externally by described one-way conduction element.
2. pfc circuit according to claim 1 is characterized in that, described control unit comprises that the feedback detection sub-unit, the PFC that connect successively analyze relatively subelement and control level output subelement;
Described feedback detection sub-unit one end is connected to the positive pole of described electric capacity, according to the Voltage-output feedback signal of described electric capacity output;
Described PFC analyzes relatively subelement, receives the feedback signal of described feedback detection sub-unit output, and analyzes comparison model according to the feedback signal that receives and built-in PFC, generates and the output drive control signal;
Described control level output subelement receives described drive control signal and generates described control signal; Wherein said control signal is control level; Described controlled switch conducting when described control level is high level, described controlled switch disconnects when described control level is low level.
3. pfc circuit according to claim 2 is characterized in that, described feedback detection sub-unit comprises resistance R 5, R6, low-voltage dc power supply, thyristor and optical coupler; Described resistance R 5 is connected with R6 afterwards and described Capacitance parallel connection; The A utmost point of described thyristor and the G utmost point are connected to described resistance R 6 two ends; The K utmost point of described thyristor links to each other with described low-voltage dc power supply is anodal; The luminous component of described optical coupler is connected in the loop that is formed by described low-voltage dc power supply and Thyristors in series; The light accepting part of described optical coupler divides with described PFC analysis comparison subelement and links to each other;
When the voltage of described electric capacity surpasses rated voltage, the conducting of described thyristor, the light accepting part of described optical coupler divides the light signal output current luminous according to its luminous component; Described output current is described feedback signal.
4. pfc circuit according to claim 2 is characterized in that, described feedback detection sub-unit comprises that one is used for the current sensor according to described electric capacity both end voltage output current; The output current of described current sensor is input to described PFC and analyzes relatively subelement; Described PFC analyzes and compares subelement according to the electric current generation drive control signal of described current sensor output.
5. pfc circuit according to claim 2 is characterized in that, described control level output subelement is PWM level output device, and when described control level was low level, the magnitude of voltage of output was zero; Described PWM level output device is adjusted the duty ratio of control level according to described drive control signal.
6. pfc circuit according to claim 1 is characterized in that, is in series with a fuse on described rectification unit two inputs or two outputs;
Described pfc circuit also comprises the short-circuit protection circuit that is connected in parallel on described electric capacity two ends; when causing the voltage at described electric capacity two ends, the unusually lasting conducting of described controlled switch surpasses rated voltage; then described short-circuit protection circuit conducting is connected with two outputs of described rectification unit and is formed Low ESR conducting loop, produces large electric current and causes described blown fuse.
7. the pfc circuit of stating according to claim 6 is characterized in that, described short-circuit protection circuit is divided into conducting control sub-loop and sub-series loop;
Described conducting control sub-loop comprises a voltage comparison module,
Described sub-series loop is second controlled switch that is connected in parallel on described electric capacity two ends;
Described voltage comparison module first input end is connected to the positive pole of described electric capacity, predeterminated voltage of the second input input;
When the magnitude of voltage of the output of described electric capacity during greater than described predeterminated voltage, forward voltage of described voltage comparison module output is given described the second controlled switch, described the second controlled switch conducting;
When the magnitude of voltage of the output of described electric capacity was equal to or less than described predeterminated voltage, negative voltage of described voltage comparison module output was given described the second controlled switch, and described the second controlled switch disconnects so that described sub-series loop disconnects.
8. pfc circuit according to claim 1 is characterized in that, described the first controlled switch can be triode or MOSET pipe;
The emitter and collector of described triode is connected on described tank circuit and described releasing in the energy loop, and the base stage of described triode is connected in the described control loop;
The drain electrode of described MOSET and source series are described tank circuit and described releasing in the energy loop, and the gate pole of described MOSET is connected in the described control loop.
9. pfc circuit according to claim 1 is characterized in that, described the first controlled switch is connected on the rear end of described inductance and described electric capacity, links to each other with the negative pole of the output of described rectification unit.
10. PFC transformer, just comprise alternating current input module, pfc circuit module and DC-DC voltage changing module, it is characterized in that described pfc circuit module is the described pfc circuit of claim 1, described alternating current input module receives the civil power input, for described pfc circuit provides alternating voltage; Described pfc circuit provides the direct voltage of input for described DC-DC voltage changing module.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2012203357905U CN202652062U (en) | 2012-07-11 | 2012-07-11 | PFC circuit and PFC transformer |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2012203357905U CN202652062U (en) | 2012-07-11 | 2012-07-11 | PFC circuit and PFC transformer |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN202652062U true CN202652062U (en) | 2013-01-02 |
Family
ID=47421100
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN2012203357905U Expired - Lifetime CN202652062U (en) | 2012-07-11 | 2012-07-11 | PFC circuit and PFC transformer |
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| CN (1) | CN202652062U (en) |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105281550A (en) * | 2014-06-18 | 2016-01-27 | 富士通株式会社 | Power supply circuit and power factor correction circuit |
| CN105790594A (en) * | 2016-05-16 | 2016-07-20 | 上海铁路通信有限公司 | DC-DC power source converter topologically structured circuit |
| CN106708164A (en) * | 2017-02-10 | 2017-05-24 | 珠海凌达压缩机有限公司 | Power factor correction circuit structure, control method and electric appliance |
| CN108702822A (en) * | 2017-05-25 | 2018-10-23 | 深圳和而泰智能照明有限公司 | A kind of LED drive circuit and LED light device |
| CN110212493A (en) * | 2019-06-05 | 2019-09-06 | 珠海格力电器股份有限公司 | Protect circuit, mainboard and electrical equipment |
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2012
- 2012-07-11 CN CN2012203357905U patent/CN202652062U/en not_active Expired - Lifetime
Cited By (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105281550A (en) * | 2014-06-18 | 2016-01-27 | 富士通株式会社 | Power supply circuit and power factor correction circuit |
| TWI578674B (en) * | 2014-06-18 | 2017-04-11 | 富士通股份有限公司 | Power supply circuit and power factor correction circuit |
| US9647527B2 (en) | 2014-06-18 | 2017-05-09 | Fujitsu Limited | Power supply circuit and power factor correction circuit |
| CN105281550B (en) * | 2014-06-18 | 2018-10-23 | 富士通株式会社 | Power circuit and circuit of power factor correction |
| CN105790594A (en) * | 2016-05-16 | 2016-07-20 | 上海铁路通信有限公司 | DC-DC power source converter topologically structured circuit |
| CN105790594B (en) * | 2016-05-16 | 2018-10-12 | 上海铁路通信有限公司 | A kind of DC-DC power source converter topology structural circuit |
| CN106708164A (en) * | 2017-02-10 | 2017-05-24 | 珠海凌达压缩机有限公司 | Power factor correction circuit structure, control method and electric appliance |
| CN106708164B (en) * | 2017-02-10 | 2018-11-02 | 珠海凌达压缩机有限公司 | Circuit of power factor correction structure, control method and electric appliance |
| CN108702822A (en) * | 2017-05-25 | 2018-10-23 | 深圳和而泰智能照明有限公司 | A kind of LED drive circuit and LED light device |
| CN110212493A (en) * | 2019-06-05 | 2019-09-06 | 珠海格力电器股份有限公司 | Protect circuit, mainboard and electrical equipment |
| CN110212493B (en) * | 2019-06-05 | 2020-04-24 | 珠海格力电器股份有限公司 | Protection circuit, mainboard and consumer |
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| CP03 | Change of name, title or address | ||
| CP03 | Change of name, title or address |
Address after: 266555 Qingdao economic and Technological Development Zone, Shandong, Hong Kong Road, No. 218 Patentee after: Hisense Video Technology Co.,Ltd. Address before: 266555 no.218, qianwangang Road, Qingdao Economic and Technological Development Zone, Shandong Province Patentee before: QINGDAO HISENSE ELECTRONICS Co.,Ltd. |
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Granted publication date: 20130102 |