CN100505487C - Single stage power factor correction converter circuit - Google Patents

Abstract

The invention is concerned with the correcting convertor of the single power factor circuit. The positive output end of the rectifier of the transformer meets the tip of the primary winding of the transformer, the bottom of the primary winding of the transformer meets the negative output end of the rectifier with the switch in the middle, the cathode of the first diode meets the positive end of the rectifier, the anode of the first diode meets the negative end of the rectifier with the circuit in series in the middle, which composes by the second diode and the second winding of the transformer, the storing capacitance anode meets the connecting point that is in the middle of the series circuit and the first diode anode, the storing capacitance cathode meets the negative end of the rectifier. The invention can eliminate the surge current generated by the power during starting up, can reduce the voltage of the storing capacitance to less than 250V, and it can recycle the magnet leakage energy of the transformer to improves power efficiency. It suits for the switch power in middle or small power.

Description

Single stage power factor correction converter circuit

technical field

The invention relates to a single-stage power factor correction converter circuit and belongs to the technical field of switching power supplies.

Background technique

For known single-stage power factor correction converters, see the article "A Review of the Improved Single-Stage Power Factor Correction AC/DC Converter Topology" published in the "Power Supply Technology Application" magazine in February 2004 and "One A single-stage power factor correction circuit" invention patent specification, the publication number is CN1545192A. Their advantage is that the control circuit is simple and the cost is slightly lower. The disadvantage of the previous article is that the surge current is large when the power is turned on, the main circuit is complex, the cost is high, the energy storage capacitor, the switching device voltage stress is high, and the power consumption is large; the disadvantage of the latter article is that the main circuit is complicated, the cost is high, and the output 100Hz ripple The voltage is large, and the surge voltage is high when the power is turned on. This cannot meet the needs of reducing costs, reducing volume and improving efficiency in some occasions, such as in products such as home appliances, office automation equipment power supplies, chargers, and electronic ballasts.

Contents of the invention

The object of the present invention is to provide a single-stage power factor correction converter circuit, the main circuit of the converter circuit is simple, the surge current can be eliminated when the power is turned on, the switching power consumption is small, the efficiency is high, and the cost is low.

The general idea of the present invention is to collect the magnetic leakage energy, part of the excitation energy (flyback switching power supply) or all the excitation energy (forward switching power supply) of the switching transformer or the energy stored in the auxiliary energy storage inductor through a certain circuit form. , when the instantaneous value of the mains voltage is less than a certain voltage, it will be supplied to the load to achieve the purpose of improving the efficiency and power factor of the switching power supply and reducing the cost of the switching power supply.

The purpose of the present invention is achieved in this way: the converter includes a rectifier bridge and a transformer, the secondary winding of the transformer is connected with an output rectifier filter circuit, the two ends of the mains are connected to the two AC input terminals of the rectifier bridge, and the positive output terminal of the rectifier bridge is connected to the primary of the transformer A switch is connected between the upper end of the winding, the lower end of the primary winding of the transformer and the negative output end of the rectifier bridge, the negative pole of the first diode is connected to the positive output end of the rectifier bridge, and the second diode is connected between the positive pole of the first diode and the negative output end of the rectifier bridge A series circuit composed of the tube and the second winding of the transformer, the positive pole of the energy storage capacitor is connected to the contact between the series circuit and the positive pole of the first diode, and the negative pole of the energy storage capacitor is connected to the negative output terminal of the rectifier bridge.

The purpose of the present invention can also be achieved in this way: the converter includes a rectifier bridge and a transformer, the secondary winding of the transformer is connected with an output rectifier filter circuit, the two ends of the mains are connected to the two AC input terminals of the rectifier bridge, and the positive output terminal of the rectifier bridge is connected to the primary of the transformer A switch is connected between the upper end of the winding, the lower end of the primary winding of the transformer and the negative output end of the rectifier bridge, the negative pole of the first diode is connected to the positive output end of the rectifier bridge, and the second diode is connected between the positive pole of the first diode and the negative output end of the rectifier bridge The series circuit composed of the tube and the second winding of the transformer, the negative electrode of the energy storage capacitor is connected to the contact between the series circuit and the positive electrode of the first diode, and the positive electrode of the energy storage capacitor is connected to the contact between the lower end of the primary winding of the transformer and the switch.

The purpose of the present invention can be achieved like this: the converter includes a rectifier bridge and a transformer, the secondary winding of the transformer is connected with an output rectifier filter circuit, the two ends of the mains are connected to the two AC input terminals of the rectifier bridge, and the positive output terminal of the rectifier bridge is connected to the primary of the transformer The upper end of the winding, the lower end of the primary winding of the transformer and the negative output end of the rectifier bridge are connected in series with a switch and an auxiliary energy storage inductance, and a series diode circuit is connected between the positive output end of the rectifier bridge and the negative output end of the rectifier bridge, and the positive pole of the energy storage capacitor is connected to The junction between the positive pole of the first diode and the negative pole of the second diode in the diode circuit, the junction between the negative pole of the energy storage capacitor connected to the switch and the auxiliary energy storage inductance, the connection between the lower end of the primary winding of the transformer and the negative output end of the rectifier bridge There is an energy regeneration capacitor indirectly.

One end of the energy regeneration capacitor is connected to the lower end of the primary winding of the transformer, and the other end is connected to the junction between the positive pole of the second diode and the negative pole of the third diode in the diode circuit, and the positive pole of the third diode is connected to the negative pole of the rectifier bridge. output.

The purpose of the present invention can also be achieved in this way: the converter includes a rectifier bridge and a transformer, the secondary winding of the transformer is connected with an output rectifier filter circuit, the two ends of the mains are connected to the two AC input terminals of the rectifier bridge, and the positive output terminal of the rectifier bridge is connected to the primary of the transformer The upper end of the winding, the lower end of the primary winding of the transformer and the negative output end of the rectifier bridge are connected in series with auxiliary energy storage inductors and switches, the lower end of the primary winding of the transformer and the negative output end of the rectifier bridge are connected with an energy regeneration capacitor, and the negative pole of the first diode is connected to The positive output terminal of the rectifier bridge, the series circuit composed of the second diode and the second winding of the transformer is connected between the positive pole of the first diode and the negative output terminal of the rectifier bridge, and the negative pole of the energy storage capacitor is connected to the positive pole of the first diode and the The junction between the series circuits, the positive pole of the energy storage capacitor is connected to the junction between the auxiliary energy storage inductance and the switch.

The object of the present invention can also be achieved like this: the converter includes a rectifier bridge and a transformer, the transformer secondary winding is connected with an output rectifier filter circuit, the mains two ends are tapped with two AC input ends of the rectifier bridge, the positive output terminal of the rectifier bridge is connected to the primary of the transformer A series auxiliary energy storage inductor and switch are connected between the upper ends of the windings, an energy regeneration capacitor is connected between the positive output end of the rectifier bridge and the upper end of the primary winding of the transformer, and two series-connected capacitors are connected between the positive output end of the rectifier bridge and the negative output end of the rectifier bridge. Diode, the negative output terminal of the rectifier bridge is connected to the lower end of the primary winding of the transformer, the negative pole of the energy storage capacitor is connected to the junction between the positive pole of the first diode connected in series and the negative pole of the second diode, and the positive pole of the energy storage capacitor is connected to the auxiliary The junction between the energy storage inductor and the switch.

The invention has the advantages of simple circuit and low cost, and can eliminate the surge current generated when the power is turned on, reduce the voltage on the energy storage capacitor to below 250V, recover and reuse the magnetic leakage energy in the transformer, and improve the power supply efficiency . It can make the mains input current have no dead zone, work in continuous conduction mode, improve the power factor of the power supply, reduce electromagnetic interference, make the switching device turn off in the state of quasi-zero voltage, and turn on in the state of zero current, reducing the Switching power consumption, and can reduce the output voltage 100Hz ripple to below 50mv. Both isolated output and non-isolated output are available. It is especially suitable for small and medium power switching power supplies, such as power supplies, chargers, electronic ballasts and other products in home appliances and office automation equipment.

Description of drawings

Fig. 1 is a circuit diagram of a first embodiment of the present invention.

Fig. 2 is a circuit diagram of a second embodiment of the present invention.

Fig. 3 is a circuit diagram of a third embodiment of the present invention.

Fig. 4 is a circuit diagram of a fourth embodiment of the present invention.

Fig. 5 is a circuit diagram of a fifth embodiment of the present invention.

Fig. 6 is a circuit diagram of a sixth embodiment of the present invention.

Detailed ways

In Fig. 1, the two ends of the mains V _i are connected to the two AC input terminals of the rectifier bridge Q, the positive output terminal of the rectifier bridge Q, the upper end of the primary winding _Np1 of the transformer T, and the negative pole of the first diode _D1 are connected; the first The anode of diode D ₁ , the anode of energy storage capacitor C _B , the second diode D ₂ (with the anode down) and the upper end of the series circuit of the second winding N _p2 of the transformer T are connected, the lower end of the primary winding N _p1 of the transformer T, the switch The upper end of S is connected; the lower end of the switch S, the negative pole of the energy storage capacitor C _B , the lower end of the series circuit of the second diode D ₂ and the second winding N _p2 of the transformer T, and the negative output end of the rectifier bridge Q are connected. The secondary winding N _s of the switching transformer T is connected with an output rectification filter circuit. When AC output is required without isolation, the secondary winding N _s of the transformer T is removed, and the AC load R _Z ( R _Z can be used as the combination load of ignition, ballast and lamp circuit or other AC load in electronic ballast).

The advantage of this embodiment is that the circuit is simple, the voltage on the energy storage capacitor C _B drops below 250V, and the surge current when the power is turned on is eliminated.

Working process: For the convenience of explanation, assume that the circuit works in the flyback state, there is a certain voltage on the energy storage capacitor C _B , and the rectifier bridge Q, the first diode D ₁ , the second diode D ₂ , and the switch S are on. State condition 1. The voltage drop can be ignored, and the instantaneous value of the mains voltage V _i is less than or greater than the voltage V _CB on the energy storage capacitor C _B , that is, V _i <V _CB , V _i >V _CB , and two stages are explained .

1. V _i <V _CB

The switch S is turned on: because Vi<V _CB , the first diode D ₁ is turned on, the rectifier bridge Q is reversely blocked, the input current of the mains is zero, and the energy storage capacitor C _B passes through the first diode D ₁ , The primary winding N _p1 of the transformer T and the switch S circuit enable the transformer T to store energy.

The switch S is turned off: the energy stored in the transformer T is transmitted to the output terminal through its secondary winding Ns, and the output voltage V ₀ is established. At this time, if the voltage V _CB on the energy storage capacitor C _B is less than or equal to the voltage V _Np2 on the second winding N _p2 of the transformer, V _Np2 = (N _p2 / _NS )V ₀ , the second winding N p2 of the transformer T passes through the second winding N _p2 Two diodes D ₂ and energy storage capacitor CB send the magnetic leakage energy in the transformer (through N _p1 , N _P2 tight coupling) and part of the excitation energy into the energy storage capacitor C _B , so that the energy stored in the transformer T when the switch S is turned on Not all are transmitted to the output terminal, which increases the 100Hz ripple voltage in the output voltage. Therefore, this embodiment is not suitable for a flyback switching power supply that requires a higher output ripple voltage. So far the circuit completes a working cycle under the condition of V _i < V _CB .

2.Vi>V _CB

The switch S is turned on: because V _i >V _CB , the first diode D1 is cut off, and the mains voltage V _i passes through the rectifier bridge Q, the primary winding N _p1 of the transformer T, and the switch S circuit to store energy in the transformer T and generate a mains input current .

The switch S is turned off: the input current of the mains is zero, and the mains energy stored by the transformer T is directly transmitted to the output terminal through its secondary winding N _s to establish an output voltage V ₀ , which improves the efficiency of the power supply. At this time, if the voltage V _CB on the energy storage capacitor C _B is less than or equal to the voltage V _Np2 on the second winding Np2 of the transformer, V _Np2 = (N _p2 / _NS )V ₀ , then the second winding N _p2 of the transformer T passes through the second winding Np2 Two diodes D ₂ and energy storage capacitor C _B send the magnetic leakage energy and part of the excitation energy in the transformer to the energy storage capacitor C _B , for example, the voltage V _CB on the energy storage capacitor C _B is greater than that on the second winding N _p2 of the transformer T Voltage V _Np2 , only the leakage magnetic energy in the transformer T charges the energy storage capacitor C _B . Make V _CB slightly larger than V _Np2 . Wait until V _i < V _CB before supplying power to the output. The ratio of transformer T winding N _p2 /N _s determines the voltage level on the energy storage capacitor C _B , which also determines the conduction width of the mains input current, that is, determines the power factor of the circuit. From the above analysis, it can be seen that the mains input current exists and is discontinuous under the condition of V _i >V _CB . So far, the circuit completes another working cycle under the condition of V _i >V _CB .

In Fig. 2, the two ends of the mains V _i are connected to the two AC input terminals of the rectifier bridge Q, the positive output terminal of the rectifier bridge Q, the upper end of the primary winding _Np1 of the transformer T, and the negative pole of the first diode _D1 are connected; the first The positive pole of diode _D1 , the negative pole of energy storage capacitor _CB , the second diode _D2 (positive pole down) and the upper end of the series circuit of the second winding N _p2 of the transformer T are connected, the lower end of the primary winding N _p1 of the transformer T, the storage The positive pole of the energy capacitor C _B is connected with the upper end of the switch S, the lower end of the switch S, the lower end of the second diode D ₂ and the second winding N _p2 of the transformer T are connected in series, the negative output end of the rectifier bridge Q is connected, and the secondary winding N of the transformer T is connected _s is connected with an output rectification and filtering circuit. When AC output is required without isolation, the secondary winding N _s of the transformer T is removed, and the AC load R _Z is connected to points A and B in the circuit.

The advantage of this embodiment is that the magnetic leakage energy in the transformer T can be directly stored in the energy storage capacitor C _B without tight coupling between the windings of the transformer T.

Working process: For the convenience of explanation, assume that the circuit works in the flyback state, there is a certain voltage on the energy storage capacitor C _B , and the rectifier bridge Q, the first diode D ₁ , the second diode D ₂ , and the switch S are in the on-state condition 1 The voltage drop is negligible, assuming that the instantaneous value of the mains voltage V _i is less than or greater than the voltage V _Np1 on the primary winding N _p1 of the transformer T, V _Np1 = (N _p1 /N _p2 ) V _CB , that is, V _i <V _Np1 , V _i >V _Np1 two stages are explained.

1. V _i < V _Np1

The switch S is turned on: because V _i <V _Np1 , the rectifier bridge Q is reversely blocked, and the input current of the mains is zero. The energy storage capacitor C _B stores energy for the transformer T through the circuit of the switch S, the second winding N _p2 of the transformer T, and the second diode D ₂ .

The switch S is turned off: the energy stored in the transformer T is transmitted to the output terminal through its secondary winding N _s to establish the output voltage V ₀ , at this time, if the voltage V _CB on the energy storage capacitor C _B is less than or equal to the voltage on the primary winding N _p1 of the transformer T Voltage V _Np1 , V _Np1 = (N _p1 / _NS )V ₀ , that is, V _CB ≤ V _Np1 , then the transformer T primary winding N _p1 drains the transformer T through the energy storage capacitor C _B and the first diode D1 loop The magnetic energy and part of the excitation energy are sent to the energy storage capacitor C _B , so that the energy stored in the transformer T when the switch S is turned on is not completely transmitted to the output terminal, so that the 100Hz ripple voltage in the output voltage V ₀ increases, so this embodiment It is not suitable to be a flyback switching power supply that requires a high output ripple voltage. So far, the circuit completes a working cycle under the condition of V _i < V _Np1 .

2.V _i >V _Np1

The switch S is turned on: because V _j >VN _p1 , the mains voltage V _i passes through the rectifier bridge Q, the primary winding N _p1 of the switching transformer T, and the switch S circuit to store energy in the transformer T and generate a mains input current.

The switch S is turned off: the mains energy stored in the transformer T is directly transmitted to the output terminal through its secondary winding Ns to establish the output voltage V ₀ , which improves the power supply efficiency. At this time, if the voltage V _CB on the energy storage capacitor C _B is less than or equal to the voltage V _Np1 on the primary winding N _p1 of the transformer T, V _Np1 = (N _p1 / _NS )V ₀ , the primary winding N _p1 of the transformer T is stored energy Capacitor C _B and the first diode D1 circuit send the magnetic leakage energy and part of the excitation energy in the transformer T to the energy storage capacitor C _B . At this time, if V _CB is greater than the voltage V _Np1 on the primary winding N _p1 of the transformer T, V _Np1 = (N _p1 /N _S )V ₀ , only the magnetic leakage energy in the transformer T charges the energy storage capacitor C _B . Make V _CB slightly larger than V _Np1 . The ratio of transformer T winding N _p1 /N _s determines the voltage level on the energy storage capacitor C _B , and the ratio of the voltage on C _B and transformer T winding N _p1 /N _p2 determines the conduction width of the mains input current, that is, determines The power factor of the circuit. It can be seen from the above analysis that the mains input current exists and is discontinuous under the condition of V _i >V _Np1 . So far, the circuit completes another working cycle under the condition of V _i >V _Np1 .

In Fig. 3, the two ends of the mains V _i are tapped to the two AC input terminals of the rectifier bridge Q, the positive output terminal of the rectifier bridge Q, the negative pole of the first diode D1, and the upper end of the primary winding N _p1 of the transformer T are connected; the first two The positive pole of the pole tube _D1 , the negative pole of the second diode _D2 , and the positive pole of the energy storage capacitor _CB are connected, the lower end of the primary winding _Np1 of the transformer T, the upper end of the switch S, and the right end of the energy regeneration capacitor _Cs are connected, and the lower end of the switch S , the negative pole of the energy storage capacitor C _B and the right end of the auxiliary energy storage inductor L _s are connected, the positive pole of the second diode D ₂ , the negative pole of the third diode D ₃ , and the left end of the energy regeneration capacitor C _s are connected, and the rectifier bridge The negative output terminal of Q, the positive pole of the third diode D ₃ , and the left end of the auxiliary energy storage inductor L _S are connected, and the secondary winding N _s of the transformer T is connected with an output rectification filter circuit. When AC output is required without isolation, remove it The secondary winding N _s of the transformer T is connected to the AC load R _Z at points A and B in the circuit.

The advantage of this embodiment is that the switch is turned off in the state of quasi-zero voltage and turned on in the state of zero current, which reduces the power consumption of the switching power supply, makes the input current of the mains work in a continuous conduction mode, and has no dead zone near zero crossing , Further improve the power factor of the switching power supply, and reduce the output voltage 100Hz ripple voltage to below 50mv.

Working process: For the convenience of explanation, assume that the circuit works in the flyback state, there is a certain voltage on the energy storage capacitor C _B , the rectifier bridge Q, the first diode D ₁ , the second diode D ₂ , and the third diode The voltage drop of the tube D ₃ and the switch S is negligible in the on-state condition, and the instantaneous value of the mains voltage V _i is greater than or less than the voltage V _CB on the energy storage capacitor C _B , that is, V _i >V _CB , V _i <V The two phases _{of CB} are described.

1.V _i >V _CB

The switch S is turned on: because V _i >V _CB , the first diode D1 is cut off, and the mains voltage V _i passes through the rectifier bridge Q, the primary winding N _p1 of the transformer T, and the auxiliary energy storage inductance L _s loop to make the transformer T, auxiliary energy storage The inductor L _s stores energy to generate the mains input current; because the energy in the auxiliary energy storage inductor L _s has been released before the switch S is turned on, the input current of the mains starts from zero, and the switch S realizes the zero-current turn-on, reducing Switch S conduction loss. The energy regeneration capacitor C _S is discharged through the circuit of the switch S, the auxiliary energy storage inductor L _S and the third diode _D3 . When the energy regeneration capacitor _CS is fully discharged, the energy regeneration capacitor _CS is reversely charged by the current in the auxiliary energy storage inductor L _S. If the current in the auxiliary energy storage inductance L _S is greater than the mains input current, the reverse voltage of the auxiliary energy storage inductance L _S will charge the energy regeneration capacitor C _S , and at the same time add up to the mains voltage through the rectifier bridge Q and transformer T The primary winding _Np1 of the transformer T, the switch S, and the auxiliary energy storage inductance L _S loop supply power to the primary winding _Np1 of the transformer T. When the current in the auxiliary energy storage inductor L _S is equal to the mains input current, the charging of the energy regeneration capacitor C _S is completed, and V _cs ≤ V _CB .

The switch S is turned off: the mains energy stored in the transformer T is directly transmitted to the output terminal through its secondary winding Ns to establish the output voltage V ₀ , which improves the power supply efficiency. At the moment when the switch S is turned off, because the current in the auxiliary energy storage inductor L _S cannot change abruptly, the polarity of the induced voltage V _ls becomes reversed, and because of the clamping effect of the voltage V _CB on the energy storage capacitor C _B , V _LS =V _CB , the auxiliary energy storage inductance L _s releases energy to charge C _B through the third diode D ₃ , the second diode D ₂ , and the energy storage capacitor C _B circuit, and at the same time, the induced voltage V on the auxiliary energy storage inductance L _{s Ls} and mains voltage V _i are added together through rectifier bridge Q, transformer T primary winding N _p1 , energy regeneration capacitor C _s , second diode D ₂ , energy storage capacitor C _B , and auxiliary energy storage inductance L _s circuit. The energy regeneration capacitor C _s is discharged, the energy storage capacitor C _B is charged, the input current of the mains starts to decrease, and the polarity of the winding voltage of the transformer T remains unchanged, so that the switch S is turned off in the state of quasi-zero voltage, and the switch S is reduced. turn-off loss.

When the auxiliary energy storage inductor L _s releases energy, the energy regeneration capacitor C _s has reversely charged to the voltage V _cs on C _s plus the voltage V _CB on the energy storage capacitor C _B is equal to the mains voltage V _i , that is, V _cs +V When _CB = V _i , the polarity of the voltage on each winding of the transformer T is reversed, the mains voltage V _i , the leakage inductance voltage, and the voltage _VN on the primary winding NP ₁ of the transformer T are added together through the rectifier bridge Q and the primary winding N of the transformer T _P1 , the energy regeneration capacitor C _s , the second diode D ₂ , the energy storage capacitor C _B , and the auxiliary energy storage inductor L _s loop to the energy regeneration capacitor C _s , the energy storage capacitor C _B continues to charge, and the mains input current continues to decrease Small. The charging of the energy regeneration capacitor C _s ends. V _cs ≥V _i +V _Np1 , V _Np1 = (N _p1 /N _s )V ₀ , when the switch S is turned off, the continuity of the mains input current is realized, and the electromagnetic interference is reduced _. >V _CB condition completes one duty cycle.

2. V _i <V _CB

The switch S is turned on: because V _i < V _CB , the first diode D ₁ is turned on, the rectifier bridge Q is reversely blocked, the mains input current V _i is zero, and the energy storage capacitor C _B passes through the first diode D ₁ , the primary winding N _p1 of the transformer T, and the switch S circuit store energy for the transformer T. The energy regeneration capacitor C _s is discharged through the circuit of the switch S, the auxiliary energy storage inductor L _s and the third diode D3. When the energy regeneration capacitor C _s is fully discharged and reversely charged to the voltage V _cs on the energy regeneration capacitor C _s (V _cs = V _Ls ) plus the mains voltage V _i is greater than or equal to the voltage V _CB on the energy storage capacitor C _B , that is, V When _cs (V _Ls )+V _i ≥V _CB , V _i +V _Ls (V _cs ) passes through the rectifier bridge Q, the primary winding N _p1 of the transformer T, the switch S, and the auxiliary energy storage inductance L _s loop to the primary winding N of the transformer T When _p1 is powered on, the mains input current is generated, the power factor of the power supply is improved, and the condition of V _cs +V _i ≥ V _CB is satisfied, and the mains input current has no dead zone.

The switch S is turned off, the energy stored in the transformer T is transmitted to the output terminal through its secondary winding N _s to establish an output voltage V ₀ , because the excitation energy stored in the transformer T cannot be sent back through the second winding N _p2 of the transformer T as shown in Figure 1 The energy storage capacitor C _B improves the power supply efficiency and reduces the 100Hz ripple voltage in the output voltage to below 50mv. At the moment when the switch S is turned off, due to the clamping effect of V _cs , the voltage polarity of each winding of T remains unchanged, so that the switch S is turned off in a quasi-zero voltage state. The energy regeneration capacitor C _s is discharged through the circuit of the second diode D ₂ , the first diode D ₁ , and the primary winding N _p1 of the transformer T. When the energy regeneration capacitor C _s is fully discharged, the voltage polarity of each winding of the transformer T begins to change On the contrary, the voltage V _Np1 on the primary winding N _P1 of the transformer T and the leakage inductance voltage series add up to charge the energy regeneration capacitor C _s in reverse, V _cs ≥ (N _p1 /N _s )V ₀ , so this circuit is at V _i < Another duty cycle is completed under V _CB conditions.

It can be known from the above analysis that under the condition of V _i >V _CB , the mains input current exists and continues no matter whether the switch S is turned on or off. Under the condition of V _i < V _CB , there is discontinuity in the mains input current when the switch S is turned on, but there is no dead zone near zero crossing, and the power factor of the power supply is further improved. At the same time, the 100Hz ripple voltage in the output voltage is reduced. The switch S is turned off in a quasi-zero-voltage state, and the switch S is turned on in a zero-current state under the condition of V _i >V _CB , thereby reducing power consumption. If a small capacitor can be connected in parallel to the input and output ends of the rectifier bridge Q in the circuit of the present invention, the effect will be better.

In Fig. 4, the two ends of the mains V _i are connected to the two AC input terminals of the rectifier bridge Q, the positive output terminal of the rectifier bridge Q, the negative pole of the first diode _D1 , and the upper end of the primary winding N _p1 of the transformer T are connected; the transformer T The lower end of the primary winding N _p1 , the upper end of the switch S, and the right end of the energy regeneration capacitor C _s are connected, the lower end of the switch S, the negative electrode of the energy storage capacitor C _B , and the right end of the auxiliary energy storage inductor L _s are connected, and the positive electrode of the first diode D1 , the negative pole of the second diode D ₂ and the positive pole of the energy storage capacitor C _B are connected, the positive pole of the second diode D ₂ , the left end of the auxiliary energy storage inductor L _s , the left end of the energy regeneration capacitor C _s , and the negative pole of the rectifier bridge Q The output ends are connected, and the secondary winding N _s of the transformer T is connected with an output rectification filter circuit. When AC output is required without isolation, the secondary winding N _s of the transformer T is removed, and the AC load is connected to points A and B in the circuit R _Z .

In Figure 5, the two ends of the mains V _i are tapped to the two AC input terminals of the rectifier bridge Q, the positive output terminal of the rectifier bridge Q, the negative pole of the first diode _D1 , and the upper end of the primary winding _Np1 of the transformer T are connected; the transformer T The lower end of the primary winding N _p1 , the upper end of the auxiliary energy storage inductor L, and the upper end of the energy regeneration capacitor C are connected, the lower end of the auxiliary energy storage inductor L _s , the positive pole of the energy storage capacitor C _B , and the upper end of the switch S are connected, and the first two poles The positive pole of the tube _D1 , the negative pole of the energy storage capacitor _CB , the second diode _D2 (positive pole down) and the upper end of the series circuit of the second winding _Np2 of the transformer T are connected, and the second diode _D2 is connected to the second winding of the transformer T The lower end of the series circuit of the two windings N _p2 , the lower end of the switch S, the lower end of the energy regeneration capacitor C _s , and the negative output end of the rectifier bridge Q are concatenated, and the secondary winding N _s of the transformer T is connected with an output rectification and filtering circuit. For AC output, the secondary winding N _s of transformer T is removed, and the AC load R _Z is connected to points A and B in the circuit.

In Figure 6, the two ends of the mains V _i are tapped to the two AC input terminals of the rectifier bridge Q, the positive output terminal of the rectifier bridge Q, the negative pole of the first diode _D1 , the upper end of the auxiliary energy storage inductor _Ls , and the energy regeneration capacitor The upper end of C _s is connected, the lower end of auxiliary energy storage inductor L _s is connected, the positive pole of energy storage capacitor C _B is connected, the upper end of switch S is connected, the lower end of switch S is connected, the upper end of primary winding N _p1 of transformer T is connected, and the lower end of energy regeneration capacitor C _s is connected. The positive pole of the first diode _D1 , the negative pole of the second diode _D2 , and the negative pole of the energy storage capacitor _CB are connected, the positive pole of the second diode _D2 , the lower end of the primary winding N _p1 of the transformer T, and the negative output of the rectifier bridge Q The secondary winding N _s of the transformer T is connected to the output rectification filter circuit. When the AC output is not needed, the secondary winding N _s of the transformer T is removed, and the A and B points in the circuit are connected to the AC load R _Z.

After understanding the working process of Fig. 1, Fig. 2 and Fig. 3 of the present invention, Fig. 4, Fig. 5 and Fig. 6 improve the power factor, reduce the 100Hz ripple voltage in the output voltage, and make the switch turn off under the quasi-zero voltage state, zero The working process of opening under the current state is easy to understand and will not be described again.

Claims (6)

1. A single-stage power factor correction converter circuit, the converter includes a rectifier bridge and a transformer, the secondary winding of the transformer is connected with an output rectifier filter circuit, and two AC input terminals of the rectifier bridge are tapped at two ends of the mains, and the rectifier bridge is characterized in that The positive output terminal of the bridge is connected to the upper end of the primary winding of the transformer, and the switch is connected between the lower end of the primary winding of the transformer and the negative output terminal of the rectifier bridge. A series circuit composed of the second diode and the second winding of the transformer is connected therebetween, the positive pole of the energy storage capacitor is connected to the junction between the series circuit and the positive pole of the first diode, and the negative pole of the energy storage capacitor is connected to the negative output terminal of the rectifier bridge. 2. A single-stage power factor correction converter circuit, the converter includes a rectifier bridge and a transformer, the secondary winding of the transformer is connected with an output rectifier filter circuit, two AC input terminals of the rectifier bridge are tapped at both ends of the mains, and the rectifier bridge is characterized in that The positive output terminal of the bridge is connected to the upper end of the primary winding of the transformer, and the switch is connected between the lower end of the primary winding of the transformer and the negative output terminal of the rectifier bridge. A series circuit composed of the second diode and the second winding of the transformer is connected between them, the negative pole of the energy storage capacitor is connected to the contact between the series circuit and the positive pole of the first diode, and the positive pole of the energy storage capacitor is connected to the lower end of the primary winding of the transformer and the switch the contact between. 3. A single-stage power factor correction converter circuit, the converter includes a rectifier bridge and a transformer, the secondary winding of the transformer is connected with an output rectifier filter circuit, two AC input terminals of the rectifier bridge are tapped at both ends of the mains, and the rectifier bridge is characterized in that The positive output terminal of the bridge is connected to the upper end of the primary winding of the transformer, a series switch and an auxiliary energy storage inductor are connected between the lower end of the primary winding of the transformer and the negative output terminal of the rectifier bridge, and a series diode circuit is connected between the positive output terminal of the rectifier bridge and the negative output terminal of the rectifier bridge , the anode of the energy storage capacitor is connected to the junction between the anode of the first diode and the cathode of the second diode in the diode circuit, the cathode of the energy storage capacitor is connected to the junction between the switch and the auxiliary energy storage inductance, the lower end of the primary winding of the transformer An energy regeneration capacitor is connected between the negative output terminal of the rectifier bridge. 4. A single-stage power factor correction converter circuit, the converter includes a rectifier bridge and a transformer, the secondary winding of the transformer is connected with an output rectifier filter circuit, and two AC input ends of the rectifier bridge are tapped at both ends of the mains, and the rectifier bridge is characterized in that The positive output terminal of the bridge, the negative pole of the first diode, and the upper end of the primary winding of the transformer are connected; The right end of the regenerative capacitor is connected, the lower end of the switch, the negative pole of the energy storage capacitor, and the right end of the auxiliary energy storage inductor are connected, the positive pole of the second diode, the negative pole of the third diode, and the left end of the energy regeneration capacitor are connected, and the rectifier bridge The negative output end, the positive pole of the third diode, and the left end of the auxiliary energy storage inductor are connected together. 5. A single-stage power factor correction converter circuit, the converter includes a rectifier bridge and a transformer, the secondary winding of the transformer is connected with an output rectifier filter circuit, and two AC input ends of the rectifier bridge are tapped at both ends of the mains, and the rectifier bridge is characterized in that The positive output terminal of the bridge is connected to the upper end of the primary winding of the transformer, the auxiliary energy storage inductor and switch are connected in series between the lower end of the primary winding of the transformer and the negative output end of the rectifier bridge, and the energy regeneration capacitor is connected between the lower end of the primary winding of the transformer and the negative output end of the rectifier bridge. A diode cathode is connected to the positive output terminal of the rectifier bridge, a series circuit composed of a second diode and the second winding of the transformer is connected between the anode of the first diode and the negative output terminal of the rectifier bridge, and the negative pole of the energy storage capacitor is connected to the The junction between the anode of the first diode and the series circuit, the anode of the energy storage capacitor is connected to the junction between the auxiliary energy storage inductance and the switch. 6. A single-stage power factor correction converter circuit, the converter includes a rectifier bridge and a transformer, the secondary winding of the transformer is connected with an output rectifier filter circuit, and two AC input ends of the rectifier bridge are tapped at both ends of the mains, and the rectifier bridge is characterized in that There is an auxiliary energy storage inductor and switch connected in series between the positive output terminal of the bridge and the upper end of the primary winding of the transformer, an energy regeneration capacitor is connected between the positive output terminal of the rectifier bridge and the upper end of the primary winding of the transformer, and the positive output terminal of the rectifier bridge and the negative output terminal of the rectifier bridge There are two diodes connected in series, the negative output terminal of the rectifier bridge is connected to the lower end of the primary winding of the transformer, the negative pole of the energy storage capacitor is connected to the junction between the positive pole of the first diode in series and the negative pole of the second diode, The positive pole of the energy capacitor is connected to the junction between the auxiliary energy storage inductance and the switch.

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