TWI536726B - Single switching switch zero - current switching series - parallel resonant converter - Google Patents

Description

Single switching switch zero current switching series-parallel resonant converter

The invention relates to a single-switching switch zero-current switching series-parallel resonant converter, in particular to an input power supply connecting an energy storage inductor series diode and a power switch, and then paralleling the diode and the power switch a resonant tank, the resonant tank is composed of a resonant capacitor series resonant inductor, and then another resonant capacitor is connected in parallel. The other resonant capacitor of the resonant tank is connected in parallel with the input end of a bridge rectifier, and the output of the bridge rectifier is connected in parallel. An input of the low-pass filter, the output of the low-pass filter is connected in parallel with a load; thus, using a single power switch to reduce switching loss under zero voltage or zero current switching, and having flexible switching characteristics, At the same time improve the operating efficiency of the converter.

In recent years, many switching elements have been used to generate resonance in the form of a sine wave at the time of switching, which allows the switch to be in a zero current or zero voltage state during commutation, and also reduces the loss of the resonant converter on the switch. At present, there are more and more reports on zero current switching (ZCS, Zero Current Switching) or zero voltage switching (ZVS, Zero Voltage Switching). For the conventional PWM converter, when used in high frequency environment, The problem of the loss in switching, resulting in the effect of efficiency, has also been significantly improved, and the resonant converter has the advantages of high conversion efficiency and high stability in high frequency environment, and has been widely used in Among various types of electronic instruments, such as computers, communication products or chargers. The E-type single-switching switch zero-current switching series-parallel resonant converter used in the present invention integrates an inductor and a capacitor in a resonant tank of a circuit in series and parallel form on the load side of the output, and is integrated into one class E DC. For the DC converter, in the use of the switch, only a single switch is used for the switching action. Compared to the general resonant converter, the two switches are used, and the volume is relatively reduced. Small, and the switching loss of one switch is also reduced, and the efficiency of the overall circuit is obviously improved. Therefore, the inventors have deliberately studied and improved the conventional resonant converter in view of the above-mentioned missing. The invention was first invented.

The main object of the present invention is to provide a single switching switch zero current which can reduce the switching loss by using a single power switch under zero voltage or zero current switching, and has the characteristics of flexible switching while improving the operating efficiency of the converter. Switch the series-parallel resonant converter.

The invention is characterized in that: the input power is connected to the energy storage inductor series diode and the power switch, and then a pair of resonant slots are connected in parallel with the diode and the power switch, wherein the resonant tank is connected by a resonant capacitor series resonant inductor; Further, another resonant capacitor is connected in parallel, and the other resonant capacitor of the resonant tank is connected in parallel with the input end of a bridge rectifier, and the output end of the bridge rectifier is connected in parallel with the input end of a low pass filter, and the output of the low pass filter Connect a load in parallel with the terminal.

For the purpose of the present invention, the preferred embodiments of the present invention are set forth in the accompanying drawings. In the second figure, the input power supply V _{dc is} connected to the energy storage inductor L _f series diode D _s and the power switch S ₁ , and then a set of resonances is connected in parallel with the diode D _s and the power switch S ₁ . slot 1, slot 1 of the resonance lines of the resonance capacitor C ₁ connected in series resonant inductor L, then the parallel resonance capacitor C _S is further composed of the resonance of the further resonant tank capacitor C _S 1 of a bridge rectifier in parallel to the input terminal 2 the bridge rectifier is connected with the second system consisting of a number of diodes (D1 ~ D4), 2 of the bridge rectifier diode (D1 ~ D4) is based fast recovery diode or Schottky diode The output of the bridge rectifier 2 is connected in parallel with the input end of a low-pass filter 3, and the output of the low-pass filter 3 is connected in parallel with a load R. The low-pass filter 3 is provided with a filter inductor L _o and a filter capacitor. The composition of C _O is connected.

When using, please refer to the first and second figures. First, input the DC voltage on the input power V _dc (power side), convert the DC voltage into a current source after the energy storage inductor L _f , and then switch the power switch S ₁ . Turning on, the power switch S ₁ selects the MOSFET transistor switch, and the parasitic reverse diode can cooperate with the reverse current flowing through the power switch S ₁ when the circuit operates, and the resonant tank 1 is composed of the resonant capacitor C ₁ series resonant inductor L after then another parallel resonance capacitor C _S composed of, in parallel with its output to bridge rectifier 2 to the high frequency AC voltage into a DC voltage, the other end of the load line by the filter inductor and the filter capacitor L _o C _o composed The low-pass filter 3, after filtering the high-frequency noise through the low-pass filter 3, can obtain a stable DC voltage to be supplied to the load R ; since the circuit is operated in a high-frequency environment, the output bridge rectifier The reverse recovery time required for the rectifying diodes ( D1 ~ D4 ) of 2 needs to be quickly restored to match the high-frequency operation mode, so the Fast Recovery diode or the Schottky diode is used. (Schottky) diode.

The waveform of the related components of the present invention, as shown in the third figure, can be obtained from the fourth to the ninth graph according to the working mode of one to six, and the six working modes are respectively:

First, the working mode one ( ωt ₀ Ωt < ωt ₁ ), as shown in the fourth figure: When the driving voltage V _{gs changes} from a low potential to a high potential, the power switch S _{1 is} turned on, and the current i _s1 on the power switch S ₁ rises from zero, and - The current value of i _L also rises from zero, so the current flows through the power switch S ₁ , because the resonant capacitor voltage V _{cs is} across the diodes D ₂ and D ₄ of the bridge rectifier 2, so that the diode D ₂ The D ₄ is in an off state, and the other set of diodes D ₁ and D _{3 are} not across the voltage, so current flows through the diodes D ₁ and D ₃ , so that the diodes D ₁ and D ₃ form a forward bias. When turned on, when the current value of the resonant capacitor current i _c1 drops to zero, the operation mode 2 is entered.

Second, the working mode two ( ωt ₁ Ωt < ωt ₂ ), as shown in the fifth figure: the driving voltage V _gs is high, the power switch S _{1 is} turned on, and - i _L current value is greater than zero, so the current flows through the power switch S ₁ , because the resonant capacitor voltage V _cs across the diodes D ₂ and D ₄ of the bridge rectifier 2, so that the diodes D ₂ and D _{4 are} presented In the off state, the other set of diodes D ₁ and D _{3 have} no voltage across, so current flows through the diodes D ₁ and D ₃ , so that the diodes D ₁ and D ₃ form a forward bias and conduct. When the resonant capacitor voltage V _{Cs of the} resonant tank 1 drops by a positive value to zero, it enters the operational mode three.

Third, the working mode three ( ωt ₂ Ωt < ωt ₃ ), as shown in the sixth figure: the driving voltage V _gs is high, the power switch S _{1 is} turned on, and - The current value of i _L is greater than zero, so the current flows through the power switch S ₁ , and since the resonant capacitor voltage V _Cs of the resonant tank 1 is negative, the diodes D ₁ and D _{3 of the} bridge rectifier 2 are in an off state, and the resonance The inductor current i _L is the resonant capacitor current i _Cs minus the resonant tank output current i _b , and the current flows through the diodes D ₂ and D ₄ , so that the diodes D ₂ and D ₄ form a forward bias and conduct, the resonant inductor The current i _L flows back to the power switch S ₁ and enters the operating mode four when the current i _Cs on the parallel resonant capacitor rises from a negative value to zero.

Fourth, the working mode four ( ωt ₃ Ωt < ωt ₄ ), as shown in the seventh figure: the driving voltage V _gs is high, the power switch S _{1 is} turned on, and - The current value of i _L is greater than zero, so the current flows through the power switch S ₁ , and since the resonant capacitor voltage V _Cs of the resonant tank 1 is negative, the diodes D ₁ and D _{3 of the} bridge rectifier 2 are in an off state, and the resonance The inductor current i _L flows through the diodes D ₂ and D ₄ such that the diodes D ₂ and D ₄ form a forward bias to conduct, and when the resonant capacitor current i _C1 rises to zero, the operation mode 5 is entered.

Five, working mode five ( ωt ₄ Ωt < ωt ₅ ), as shown in the eighth figure: the driving voltage V _gs is high, the power switch S _{1 is} turned on, and - The current value of i _L is greater than zero. Since the resonant capacitor voltage V _Cs of the resonant tank 1 is negative, the diodes D ₁ and D _{3 of the} bridge rectifier 2 are in an off state, and the resonant inductor current i _L is a resonant capacitor current i. _Cs subtracts the resonant tank output current i _b , current flows through the diodes D ₂ and D ₄ , so that the diodes D ₂ and D ₄ form a forward bias and conduct, and the resonant inductor current i _L flows back to the power switch S _1. When the switch current i _S1 drops to zero, it enters the working mode six.

Sixth, work mode six ( ωt ₅ Ωt < ωt ₆ ), as shown in the ninth figure: the driving voltage V _{gs changes} from a high potential to a low potential, the power switch S ₁ is turned off, the switching current i _S1 is zero, and - The current value of i _L is also zero, and the resonant capacitor voltage V _Cs rises from zero, since the resonant capacitor voltage V _{Cs is} across the diodes D ₂ and D ₄ of the bridge rectifier 2, so the diodes D ₂ and D ₄ exhibits an off state, and the other set of diodes D ₁ and D _{3 have} no cross voltage, so current flows through the diodes D ₁ and D ₃ , so that the diodes D ₁ and D ₃ form a forward bias and conduct. , when - When the current value of i _L rises from zero, the driving voltage V _{gs changes} from low potential to high potential. At this time, the power switch S _{1 is} switched on and then returns to the working mode one to complete a cycle of one cycle.

The driving voltage V _gs and the switching voltage V _{ds are} measured waveforms, as shown in the tenth figure, the CH1:X axis: 2.5 μs/div, the Y axis: 10 V/div; CH2: X axis: 2.5 μs/div, Y Axis: 100V/div.

The stored energy inductor voltage V _Lf and the stored energy inductor current i _Lf measured waveform diagram, as shown in the eleventh figure, its CH1: X axis: 2.5μs / div, Y axis: 100V / div; CH2: X axis: 2.5 Μs/div, Y axis: 200 mA/div.

The driving voltage V _gs and the switching current i _s1 measured waveform diagram, as shown in the twelfth figure, its CH1: X axis: 2.5 μs / div, Y axis: 10 V / div; CH2: X axis: 2.5 μs / div, Y axis: 500 mA / div.

The resonant capacitor voltage V _c1 and the resonant capacitor current i _{c1 are} measured waveforms, as shown in the thirteenth figure, the CH1:X axis: 2.5 μs/div, the Y axis: 100 V/div; CH2: X axis: 2.5 μs/ Div, Y axis: 500mA/div.

The resonant inductor voltage V _L and the resonant inductor current i _{L are} measured waveforms, as shown in Fig. 14, the CH1: X axis: 2.5 μs/div, the Y axis: 100 V/div; CH2: X axis: 2.5 μs/ Div, Y axis: 500A/div.

The resonant capacitor voltage V _cs and the resonant capacitor current i _cs measured waveform diagram, as shown in the fifteenth figure, its CH1: X axis: 2.5 μs / div, Y axis: 100 V / div; CH2: X axis: 2.5 μs / Div, Y axis: 500mA/div.

The resonant tank output voltage V _b and the resonant tank output current i _b measured waveform diagram, as shown in the sixteenth figure, its CH1: X axis: 2.5μs / div, Y axis: 10V / div; CH2: X axis: 2.5 Μs/div, Y axis: 200 mA/div.

The measured voltage waveforms of the diode voltages V _{D1 , D3} and the diode currents i _{D1 and D3 are} as shown in FIG. 17 , and the CH1:X axis is 2.5 μs/div, and the Y axis is 50 V/div; CH 2 : X axis: 2.5 μs/div, Y axis: 200 mA/div.

The measured voltage waveforms of the diode voltages V _{D2 , D4} and the diode currents i _{D2 and D4 are} as shown in the eighteenth figure, and the CH1:X axis: 2.5 μs/div, the Y axis: 20 V /div; CH2: X axis: 2.5 μs/div, Y axis: 200 mA/div.

The filtered inductor voltage V _Lo and the filtered inductor current i _{Lo are} measured waveforms, as shown in the nineteenth figure, the CH1:X axis: 2.5 μs/div, the Y axis: 20 V /div; CH2: X axis: 2.5 μs/ Div, Y axis: 200mA/div.

The filter capacitor voltage V _co and the filter capacitor current i _co measured waveform diagram, as shown in the twentieth diagram, its CH1: X axis: 2.5 μs / div, Y axis: 20 V / div; CH2: X axis: 2.5 μs / Div, Y axis: 200mA/div.

The measured voltage V _o and the output current i _o measured waveform diagram, as shown in the twenty-first figure, its CH1: X axis: 2.5 μs / div, Y axis: 20 V / div; CH2: X axis: 2.5 μs / div , Y axis: 200 mA / div.

The invention can make the power switch S ₁ operate in a zero voltage or zero current state by selecting appropriate component parameters, switching frequency and resonance frequency, so as to reduce power loss of the power switch S ₁ during high frequency switching, and can also improve power. The heat dissipation problem of the switch S ₁ increases the efficiency of the DC conversion DC.

The invention adopts a single-switch E-type resonance type converter, and has the advantages of high conversion efficiency and good stability when the resonant converter operates at a high operating frequency, and is often used in DC-to-AC in today's use. Change In the flow device, since the E-type resonant type circuit has only one single switch, the switching loss is reduced, and the components of the circuit are also few, so the E-type resonant circuit can have higher efficiency than the general resonant circuit. Moreover, such circuits have the characteristics of Zero Voltage Switching, which can minimize the switching loss and achieve the soft-switching characteristics, while the flexible switching technology refers to reducing the voltage during the switching process. The overlap with the current area, and zero voltage switching means that the voltage across the switch drops to zero before the switch is turned on, so that when the switch is turned on, it does not overlap with the current on the switch, resulting in conduction loss, and zero. The current switched to the on-current on the switch must be maintained at zero before the switch is turned off so that it does not overlap with the cross-over voltage on the switch, resulting in a turn-off loss.

The invention adds a set of bridge rectifiers 2 from the load R end of the E-type converter circuit. When the current is passed from the output end of the resonant tank 1 through the bridge rectifier 2, it will be rectified into direct current, and then passed through a set of filter inductors. The low-pass filter 3 composed of L _o and the filter capacitor C _o is filtered into a stable direct current to the load R , and the output current and the output voltage can be controlled by adjusting the switching frequency. This circuit not only has a simple circuit structure and a control circuit. The design is easy. Since the circuit only needs a single power switch S ₁ , which is different from the conventional dual switch of the D-type resonant converter, the switching loss of the switch can be reduced, and the characteristic of flexible switching can be effectively reduced. Switch losses and improve converter operating efficiency.

In summary, the embodiments of the present invention have indeed achieved the intended purpose and the efficacy of use, and the same structural features are not known and commonly used, so the present invention can meet the requirements of the invention patent, and is proposed according to law. Apply, please apply for an early conclusion, and grant a patent, and I am deeply impressed.

1‧‧‧Resonance slot

2‧‧‧Bridge rectifier

3‧‧‧Low-pass filter

V _dc ‧‧‧ input power

L _f ‧‧‧ storage inductor

V _Lf ‧‧‧ storage inductor voltage

i _Lf ‧‧‧ Energy storage inductor current

D _s ‧‧‧dipole

S ₁ ‧‧‧Power switch

V _ds ‧‧‧Switching voltage

i _s1 ‧‧‧Switch current

V _gs ‧‧‧ drive voltage

C ₁ ‧‧‧Resonance Capacitor

V _c1 ‧‧‧resonant capacitor voltage

i _c1 ‧‧‧resonant capacitor current

L ‧‧‧Resonance inductance

V _L ‧‧‧Resonance Inductor Voltage

i _L ‧‧‧Resonance inductor current

C _S ‧‧‧Resonance Capacitor

V _cs ‧‧‧resonant capacitor voltage

i _cs ‧‧‧resonant capacitor current

V _b ‧‧‧resonance slot output voltage

i _b ‧‧‧resonance slot output current

D1 ~ D4 ‧‧‧ diode

V _D1 ~V _D4 ‧‧‧ diode voltage

i _D1 ~ i _D4 ‧‧‧ diode current

L _o ‧‧‧Filter inductor

V _Lo ‧‧‧Filtering Inductor Voltage

i _Lo ‧‧‧Filtering inductor current

C _O ‧‧‧Filter Capacitor

V _co ‧‧‧Filter capacitor voltage

i _co ‧‧‧Filter capacitor current

R ‧‧‧load

V _o ‧‧‧output voltage

i _o ‧‧‧Output current

The first figure is a circuit diagram of an embodiment of the present invention.

The second figure is a block diagram of an embodiment of the present invention.

The third figure is a waveform diagram of an embodiment of the present invention.

The fourth figure is an equivalent circuit diagram of the working mode 1 of the embodiment of the present invention.

The fifth figure is an equivalent circuit diagram of the working mode 2 of the embodiment of the present invention.

The sixth figure shows an equivalent circuit diagram of the working mode 3 of the embodiment of the present invention.

The seventh figure is an equivalent circuit diagram of the working mode 4 of the embodiment of the present invention.

The eighth figure is an equivalent circuit diagram of the working mode 5 of the embodiment of the present invention.

The ninth figure is an equivalent circuit diagram of the working mode 6 of the embodiment of the present invention.

The tenth figure shows the measured waveforms of the driving voltage V _gs and the switching voltage V _{ds according to the} embodiment of the present invention.

FIG. 11 is a measured waveform diagram of the storage inductor voltage V _Lf and the storage inductor current i _{Lf according to an} embodiment of the present invention.

FIG. 12 is a waveform diagram of the driving voltage V _gs and the switching current i _{s1 according to an} embodiment of the present invention.

FIG. 13 is a waveform diagram of the resonant capacitor voltage V _c1 and the resonant capacitor current i _{c1 according to an} embodiment of the present invention.

FIG. 14 is a waveform diagram of the resonant inductor voltage V _L and the resonant inductor current i _{L according to an} embodiment of the present invention.

The fifteenth figure is a measured waveform diagram of the resonant capacitor voltage V _cs and the resonant capacitor current i _{cs according to the} embodiment of the present invention.

Figure 16 is a waveform diagram of the resonant tank output voltage V _b and the resonant tank output current i _{b in the} embodiment of the present invention.

Figure 17 is a diagram showing measured waveforms of diode voltages V _{D1 and D3} and diode currents i _{D1 and D3 according to an} embodiment of the present invention.

The eighteenth graph is a measured waveform diagram of the diode voltages V _{D2 and D4} and the diode currents i _{D2 and D4 according to the} embodiment of the present invention.

FIG. 19 is a waveform diagram of the filtered inductor voltage V _Lo and the filtered inductor current i _{Lo according to an} embodiment of the present invention.

FIG. 20 is a waveform diagram of the filter capacitor voltage V _co and the filter capacitor current i _{co according to an} embodiment of the present invention.

The twenty-first figure shows the measured waveforms of the output voltage V _o and the output current i _{o according to the} embodiment of the present invention.

1‧‧‧Resonance slot

2‧‧‧Bridge rectifier

3‧‧‧Low-pass filter

V _dc ‧‧‧ input power

L _f ‧‧‧ storage inductor

i _Lf ‧‧‧ Energy storage inductor current

D _s ‧‧‧dipole

S ₁ ‧‧‧Power switch

i _s1 ‧‧‧Switch current

V _gs ‧‧‧ drive voltage

C ₁ ‧‧‧Resonance Capacitor

i _c1 ‧‧‧resonant capacitor current

L ‧‧‧Resonance inductance

C _S ‧‧‧Resonance Capacitor

V _cs ‧‧‧resonant capacitor voltage

i _cs ‧‧‧resonant capacitor current

i _b ‧‧‧resonance slot output current

D1 ~ D4 ‧‧‧ diode

V _D1 ~ V _D4 ‧‧‧ diode voltage

L _o ‧‧‧Filter inductor

C _O ‧‧‧Filter Capacitor

R ‧‧‧load

V _o ‧‧‧output voltage

i _o ‧‧‧Output current

Claims (1)

A single-switching switch zero-current switching series-parallel resonant converter mainly has an input power supply connected to an energy storage inductor series diode and a power switch, and a parallel resonant tank is arranged on the diode and the power switch, The resonant tank is composed of a resonant capacitor series resonant inductor, and then another resonant capacitor is connected in parallel. The other resonant capacitor of the resonant tank is connected in parallel with the input end of a bridge rectifier, and the output of the bridge rectifier is connected in parallel with a low pass filter. At the input end, the output of the low-pass filter is connected in parallel with a load; thus, using a single power switch to reduce switching loss under zero voltage or zero current switching, and having flexible switching characteristics, while improving the converter Operational efficiency.