TWI485962B - Zero Current Switching Parallel Load Resonant Converter - Google Patents

Description

Zero current switching parallel load resonant converter

The invention relates to a zero current switching parallel load resonance converter, in particular to an input power supply connection choke inductor series forward diode and power switch, and then a parallel group on the forward diode and the power switch The resonant tank and the resonant tank are composed of a resonant inductor series resonant capacitor, the resonant tank is connected in parallel with the bridge rectifier, and finally the low-pass filter and the load are connected in parallel; thus, the switching can be reduced by using a single power switch under zero current switching. Loss, and features flexible switching and boosting to improve converter operating efficiency.

According to the traditional power electronic products, most of them use traditional hard switching, because the circuit has a considerable degree of reliability, and the circuit structure is simple, but because the power transistor switch operates under high frequency switching, due to its circuit The switching loss and the Spike effect make the product quality bottleneck, especially when applied to an uninterruptible power supply or motor driver, which will make the pulse width modulation (PWM) The switching frequency cannot be improved, so good characteristics and noise reduction cannot be obtained. If the above disadvantages are to be improved, the switching frequency must be increased, but the loss caused by the switching is also increased due to the increase of the frequency, so flexible switching must be developed. The way (for example: zero current switching), this switching method will solve the above problems; if the power transistor switch has the characteristics of flexible switching, the switching loss can be greatly reduced, so the conversion efficiency can be improved, and the product can be improved. Reduced size and weight reduction; and in order to make the power transistor switch flexible Switching characteristics, the circuit must be resonant, through the switching of the power transistor switch, to provide a circuit wave drive voltage, using capacitors and inductors to oscillate, and generate a waveform similar to the sine wave, so that the power transistor switch is doing When switching, it is in a state of zero current, and the resonant capacitor, resonant inductor, and power transistor switch must be able to withstand high voltage or high current stress, while the resonant converter is different from the conventional switching converter in that it is a resonant converter. The power transistor switch operates in the characteristics of Zero-Current-Switching (ZCS), while the zero-current switching means that the on-current on the power transistor switch must drop to zero before the power transistor switch is turned off. The overlap with the voltage across the power transistor switch results in a loss of cut-off, while the resonant converter combines the appropriate component parameters, switching frequency, and resonant frequency to allow the power transistor switch to have zero current at high frequency switching. Switching characteristics, thus overcoming switching losses and electromagnetic interference (EMI) Problem.

A bad switching method is the main cause of power loss in the converter circuit. During the transition of the power transistor switch to the on or off state, if the voltage or current on the power transistor switch is not zero, then the voltage and current are The waveform area will overlap and cause power loss. When the switching frequency is increased, the switching of the power transistor switch occurs more frequently, and the power loss also increases. In theory, the resonant converter has flexibility. The switching characteristics, and can operate at a higher switching frequency, so that a smaller output filter component can be selected to reduce the circuit size and weight, and the switching loss and electromagnetic interference are compared with the conventional switching converter. The situation can be greatly improved, and there is no need to connect the series or parallel buffer circuit beside the power transistor switch. The conversion efficiency of the circuit can be improved. The resonance mode of the resonant tank circuit and the resonant effect of the switching of the power transistor switch will be different by the difference between the resonant tank circuit and the load connection mode, and in different converter circuits, According to the needs of the circuit, a resonant tank circuit of a suitable resonance form can be selected for design. Therefore, the inventors of the present invention have invented the present invention in view of the above-mentioned lack of the above-mentioned resonant converter. invention.

The main object of the present invention is to provide a zero current switching parallel load that can reduce the switching loss by using a single power switch under zero current switching, and has the characteristics of flexible switching and boosting to improve the operating efficiency of the converter. Resonant converter.

The invention is characterized in that: the input power supply is connected with the choke inductor series forward diode and the power switch (the connection mode is the positive end of the input power supply connected to the positive end of the choke inductor, and the negative end of the choke inductor is connected to the second direction) The anode of the polar body, the cathode of the forward diode is connected to the drain of the power switch, the source of the power switch is connected to the negative terminal of the input power supply, and the forward two-pole system is set as a fast recovery diode or Schottky II In the polar body, a pair of resonant slots are connected in parallel with the forward diode and the power switch, and the resonant tank is composed of a resonant inductor series resonant capacitor (the connection mode is such that the positive end of the resonant inductor is connected to the anode of the forward diode, The negative end of the resonant inductor is connected to the positive end of the resonant capacitor, and the negative end of the resonant capacitor is connected to the source of the power switch. The resonant tank is connected to the bridge rectifier, and finally the low-pass filter and the load are connected in parallel.

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, there is mainly an input power supply V _dc connection choke inductor L _f series forward diode D _s and power switch S (the connection mode is the positive terminal of the input power supply V _dc connected to the choke inductor L _f the positive terminal of the choke inductor L _f anode connected to the negative terminal of the forward direction of the diode D _s, cis electrode, a source electrode connected to the power switch S V _dc input power to the cathode of the power switch S is connected the drain of the diode D _s Negative terminal), where the input power V _dc is set as the current source, and the forward diode D _s is set as the Fast Recovery or Schottky diode, the power switch S system It is set as a MOSFET transistor switch, and then a pair of resonant tanks 1 are connected in parallel with the forward diode D _s and the power switch S. The resonant tank 1 is composed of a resonant inductor L _r series resonant capacitor C _r (the connection mode is resonance) The positive terminal of the inductor L _r is connected to the anode of the forward diode D _s , and the negative terminal of the resonant inductor L _r is connected to the resonant capacitor C _r The positive terminal, the negative terminal of the resonant capacitor C _r is connected to the source of the power switch S ), the resonant tank 1 is connected to the bridge rectifier 2, and the bridge rectifier 2 is provided with a plurality of diodes D1 to D4 connected, the bridge rectifier The two diodes D1~D4 are fast recovery diodes or Schottky diodes, and finally parallel low-pass filter 3 and load R , low-pass filter 3 The filter inductor L _{o is} connected to the filter capacitor C _o .

When using, please also refer to the first and second diagrams. First, input the DC voltage on the input power V _dc (DC power supply side), and input the current I _dc through the choke inductor L _{f to} convert the DC voltage into a stable 扼The current inductor current i _{Lf is used} to drive the power switch S to switch on. The power switch S selects the MOSFET transistor switch, and the parasitic reverse diode can cooperate with the operation mode of the circuit, and the resonant tank 1 is composed of the resonant inductor L _{r .} The series resonant capacitor C _r is composed of a switching of the power switch S , and provides a one-wave driving voltage V _{gs of the} resonant tank 1 , which is oscillated by the resonant inductor L _r and the resonant capacitor C _r , thereby achieving the purpose of zero current switching. In order to reduce the switching loss of the circuit, when the resonant tank 1 generates a high-frequency alternating voltage via resonance, the high-frequency alternating current voltage is converted into a direct current voltage by the bridge rectifier 2 connected in parallel to the resonant tank 1, and then subjected to low-pass filtering. 3 and the adjustment voltage to remove high frequency noise, a load R to provide a stable DC output voltage v _o; due to the high frequency circuit is operating in the working mode, the output terminal of the bridge rectifier 2 Rectifying diodes D1 ~ D4 to be reverse recovery time required is very short, with high frequency to the operating mode, so the use of fast recovery diodes (Fast Recovery) or a Schottky diode (Schottky); circuit because It is a circuit architecture of a parallel load resonant converter. This circuit architecture has a boosting feature that boosts the output voltage v _o and increases the output current i _o .

The invention can obtain the third to eighth pictures according to its working mode one to six, and the six working modes are respectively:

First, the working mode one ( ωt ₀ Ωt < ωt ₁ ), as shown in the third figure: at ωt ₀ , the square wave driving voltage V _gs changes from a low potential to a high potential, the power switch S is switched to be turned on, and the forward diode D _{s is} also turned on at the same time. The power switch voltage v _s is zero. Since the choke inductor current i _{Lf is} greater than the resonant inductor current i _Lr , ie i _Lf - i _Lr >0, the i _Lf - i _Lr current flows through the power switch S , and the power switch current i _s is Zero gradually rises, i _Lf - i _Lr current is equal to power switch current i _s , resonant inductor current i _Lr is positive value, and flows through resonant capacitor C _r and charges it. At this time, resonant capacitor voltage v _Cr is positive value, bridge The diodes D ₁ and D ₄ of the rectifier 2 are turned on. When the resonant capacitor voltage v _Cr reaches a peak value, the resonant inductor current i _Lr starts to decrease, and when the resonant inductor current i _Lr falls to zero, the operation mode 2 is entered.

Second, the working mode two ( ωt ₁ Ωt < ωt ₂ ), as shown in the fourth figure: at ωt ₁ , the square wave driving voltage V _gs is high, the power switch S is turned on, the forward diode D _{s is} also turned on, and the power switching voltage v _s is zero. The resonant inductor current i _Lr continues to decrease from zero to negative, so i _Lf - i _Lr >0, so i _Lf - i _Lr current flows through the power switch S , the power switch current i _s continues to rise, i _Lf - i _Lr current is equal The power switch current i _s , at which time the resonant capacitor voltage v _{Cr is} still positive, the diodes D ₁ and D ₄ of the bridge rectifier 2 are turned on, the resonant capacitor voltage v _Cr starts to decrease from the peak value, and when the resonant capacitor voltage v _Cr When it drops to zero, it enters working mode three.

Third, the working mode three ( ωt ₂ Ωt < ωt ₃ ), as shown in the fifth figure: at ωt ₂ , the square wave driving voltage V _gs is high, the power switch S is turned on, the forward diode D _{s is} also turned on, and the power switching voltage v _s is zero. The resonant inductor current i _{Lr is} still negative, so i _Lf - i _Lr >0, so i _Lf - i _Lr current flows through the power switch S , the power switch current i _s reaches the peak and begins to fall, i _Lf - i _Lr current Equal to the power switch current i _s , when the resonant capacitor voltage v _Cr decreases from zero to negative, the diodes D ₂ and D ₃ of the bridge rectifier 2 are turned on, and the resonant inductor current i _Lr starts to rise gradually, when the resonant inductor current i _{When Lr} rises to zero, it enters working mode four.

Fourth, the working mode four ( ωt ₃ Ωt < ωt ₄ ), as shown in the sixth figure: at ωt ₃ , the square wave driving voltage V _gs is high, the power switch S is turned on, the forward diode D _{s is} also turned on, and the power switching voltage v _s is zero. At this time, the choke inductor current i _{Lf is} still greater than the resonant inductor current i _Lr , so i _Lf - i _Lr >0, so i _Lf - i _Lr current flows through the power switch S , and the power switch current i _s continues to decrease, i _Lf - The i _Lr current is equal to the power switch current i _s , the resonant capacitor voltage v _Cr is a negative value, the diodes D ₂ and D ₃ of the bridge rectifier 2 are turned on, and the resonant inductor current i _Lr gradually rises from zero and flows through the resonant capacitor. C _r is charged and the resonant capacitor voltage v _Cr starts to rise gradually. When the power switch current i _s drops to zero, the power switch S switches to off and enters the operating mode five.

Five, working mode five ( ωt ₄ Ωt < ωt ₅ ), as shown in the seventh figure: at ωt ₄ , the square wave driving voltage V _gs is high, the power switch S is turned off, the forward diode D _{s is} also turned off, and the power switching voltage v _s is zero. Since there is no current on the power switch S , the power switch current i _s is zero, so the i _Lf - i _Lr current does not flow through the power switch S , the i _Lf - i _Lr current is also zero, and the forward diode D _s generates a negative forward diode voltage v _Ds to prevent current from flowing backward through the power switch S. At this time, the resonant capacitor voltage v _Cr is negative, and the diodes D ₂ and D ₃ of the bridge rectifier 2 are turned on. The resonant inductor current i _Lr is a positive value and continues to flow through the resonant capacitor C _r and charges it. The resonant capacitor voltage v _Cr continues to rise. When the square wave driving voltage V _gs changes from a high potential to a low potential, the resonant capacitor voltage v _Cr rises to zero and enters mode of operation six.

Sixth, work mode six ( ωt ₅ Ωt < ωt ₆ ), as shown in the eighth figure: At ωt ₅ , the square wave drive voltage V _gs is low, the power switch S is turned off, the forward diode D _{s is} also turned off, and the power switch voltage v _s is zero gradually rises, since there is no current on the power switch S, the power switch current i _s is zero, so i _Lf - i _Lr current does not flow through the power switch S, i _Lf - i _Lr current is also zero and there is a choke inductor The current i _Lf is positive and continues to flow through the resonant capacitor C _r and charges it. The resonant capacitor voltage v _Cr gradually rises from zero, and the diodes D ₁ and D ₄ of the bridge rectifier 2 are turned on, when the square wave is driven. When the voltage V _gs changes from a low potential to a high potential, the power switching voltage v _s drops to zero, and the power switch S is switched to be turned on, returning to the operating mode one.

The measured waveform of the input power V _dc and the input current I _dc , as shown in the ninth figure, has CH1: X axis: 5 μs/div, Y axis: 50 V /div; CH2: X axis: 5 μs/div, Y axis : 1A/div.

The measured waveform of the choke inductor voltage v _Lf and the choke inductor current i _Lf , as shown in the tenth figure, has CH1: X axis: 5 μs/div, Y axis: 100 V/div; CH2: X axis: 5 μs/ Div, Y axis: 1A/div.

The measured waveform of the square wave driving voltage V _gs and the power switching current i _s , as shown in FIG. 11 , is CH1: X axis: 5 μs/div, Y axis: 20 V /div; CH 2 : X axis: 5 μs/ Div, Y axis: 2A/div.

The measured waveform of the power switching voltage v _s and the power switching current i _s , as shown in the twelfth figure, has CH1: X axis: 5 μs/div, Y axis: 100 V/div; CH2: X axis: 5 μs/div , Y axis: 2A / div.

The measured waveform of the square wave driving voltage V _gs and the power switching voltage v _s , as shown in the thirteenth figure, has CH1: X axis: 5 μs/div, Y axis: 20 V /div; CH2: X axis: 5 μs/ Div, Y axis: 100V/div.

The measured waveform of the forward diode voltage v _Ds and the forward diode current i _Ds , as shown in FIG. 14 , has CH1: X axis: 5 μs/div, Y axis: 100 V/div; CH2: X axis: 5 μs/div, Y axis: 2 A/div.

The measured waveform of the resonant inductor voltage v _Lr and the resonant inductor current i _Lr , as shown in the fifteenth figure, has CH1: X axis: 5 μs/div, Y axis: 100 V/div; CH2: X axis: 5 μs/div , Y axis: 2A / div.

The measured waveform of the resonant capacitor voltage v _Cr and the resonant capacitor current i _Cr , as shown in the sixteenth figure, has CH1: X axis: 5 μs/div, Y axis: 100 V/div; CH2: X axis: 5 μs/div , Y axis: 2A / div.

The measured waveform of the square wave driving voltage V _gs and the resonant input voltage v _a , as shown in FIG. 17 , is CH1: X axis: 5 μs/div, Y axis: 20 V /div; CH 2 : X axis: 5 μs/ Div, Y axis: 100V/div.

The measured waveform of the resonant input voltage v _a and the resonant output voltage v _b , as shown in the eighteenth figure, has CH1: X axis: 5 μs/div, Y axis: 100 V/div; CH2: X axis: 5 μs/div , Y axis: 100V / div.

The measured waveform of the resonant output voltage v _b and the resonant output current i _b , as shown in the nineteenth figure, has CH1: X axis: 5 μs/div, Y axis: 100 V/div; CH2: X axis: 5 μs/div , Y axis: 500mA / div.

The measured waveforms of the diode voltages v _D1 , v _D4 and the diode currents i _D1 , i _D4 , as shown in the twentieth diagram, have CH1: X axis: 5 μs/div, Y axis: 100 V/div; CH2: X axis: 5 μs/div, Y axis: 500 mA/div.

The measured waveforms of the diode voltages v _D2 , v _D3 and the diode currents i _D2 and i _D3 , as shown in the twenty-first figure, have CH1: X axis: 5 μs/div, and Y axis: 100 V/div. CH2: X axis: 5 μs/div, Y axis: 500 mA/div.

The measured waveform of the rectified input voltage v _b and the rectified output voltage v _c , as shown in the twenty-second diagram, has CH1: X axis: 5 μs/div, Y axis: 100 V/div; CH2: X axis: 5 μs/ Div, Y axis: 100mA/div.

The measured waveform of the filtered inductor voltage v _Lo and the filtered inductor current i _Lo , as shown in the twenty-third figure, has CH1: X axis: 5 μs/div, Y axis: 100 V/div; CH2: X axis: 5 μs/ Div, Y axis: 500mA/div.

The measured waveform of the filter capacitor voltage v _Co and the filter capacitor current i _Co , as shown in the twenty-fourth figure, has CH1: X axis: 5 μs/div, Y axis: 100 V/div; CH2: X axis: 5 μs/ Div, Y axis: 100mA/div.

The measured waveform of the output voltage v _o and the output current i _o , as shown in the twenty-fifth figure, has CH1: X axis: 5 μs/div, Y axis: 50 V/div; CH2: X axis: 5 μs/div, Y axis: 500 mA / div.

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

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. In the inverter, 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 be higher than the general resonant circuit. Efficiency, and such circuits have the characteristics of Zero Current Switching, which allows the switch to minimize switching losses and achieve Soft-Switching characteristics. Flexible switching technology refers to the process of reducing switching. Medium voltage and current plane The size of the overlap, and the zero current switching 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 cut-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, it can reduce the switching loss of the switch, and has the characteristics of flexible switching and boosting, so Effectively reduce switching 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

V _gs ‧‧‧ square wave drive voltage

I _dc ‧‧‧ input current

L _f ‧‧‧ Choke inductor

v _Lf ‧‧‧ Choke inductor voltage

i _Lf ‧‧‧扼 inductor current

D _s ‧‧‧ forward diode

v _Ds ‧‧‧ forward diode voltage

i _Ds ‧‧‧ forward diode current

S ‧‧‧Power switch

v _s ‧‧‧Power Switch Voltage

i _s ‧‧‧Power switch current

L _r ‧‧‧Resonance inductance

v _Lr ‧‧‧Resonance inductor voltage

i _Lr ‧‧‧Resonance inductor current

C _r ‧‧‧resonance capacitor

v _Cr ‧‧‧resonant capacitor voltage

i _Cr ‧‧‧resonant capacitor 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

v _a ‧‧‧Resonant input voltage

v _b ‧‧‧Resonance output voltage

i _b ‧‧‧Resonance output current

v _b ‧‧‧Rectified input voltage

v _c ‧‧‧Rectified output voltage

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 an equivalent circuit diagram of the working mode 1 of the embodiment of the present invention.

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

The fifth figure is an equivalent circuit diagram of the working mode 3 of the embodiment of the present invention.

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

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

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

The ninth figure is a measured waveform diagram of the input power source V _dc and the input current I _{dc according to an} embodiment of the present invention.

The tenth figure shows the measured waveform of the choke inductor voltage v _Lf and the choke inductor current i _{Lf according to} the embodiment of the present invention.

FIG. 11 is a measured waveform diagram of a square wave driving voltage V _gs and a power switching current i _{s according to an} embodiment of the present invention.

FIG. 12 is a measured waveform diagram of the power switch voltage v _s and the power switch current i _{s according to an} embodiment of the present invention.

FIG. 13 is a measured waveform diagram of a square wave driving voltage V _gs and a power switching voltage v _{s according to an} embodiment of the present invention.

FIG. 14 is a measured waveform diagram of the forward diode voltage v _Ds and the forward diode current i _{Ds according} to an embodiment of the present invention.

The fifteenth figure is a measured waveform diagram of the resonant inductor voltage v _Lr and the resonant inductor current i _{Lr according to} the embodiment of the present invention.

Figure 16 is a graph showing the measured waveforms of the resonant capacitor voltage v _Cr and the resonant capacitor current i _{Cr in} the embodiment of the present invention.

A seventeenth embodiment of FIG square wave drive voltage V _gs Found resonant input voltage v _a waveform diagram of the embodiment of the present invention is shown based.

Figure 18 is a graph showing measured waveforms of the resonant input voltage v _a and the resonant output voltage v _{b according to an} embodiment of the present invention.

The nineteenth figure is a measured waveform diagram of the resonant output voltage v _b and the resonant output current i _{b according to} the embodiment of the present invention.

FIG. 20 is a measured waveform diagram of the diode voltages v _D1 , v _D4 and the diode currents i _D1 and i _{D4 according to} the embodiment of the present invention.

The twenty-first figure shows the measured waveforms of the diode voltages v _D2 and v _D3 and the diode currents i _D2 and i _{D3 according to} the embodiment of the present invention.

The twenty-second figure is a measured waveform diagram of the rectified input voltage v _b and the rectified output voltage v _{c according to an} embodiment of the present invention.

FIG. 23 is a measured waveform diagram of the filter inductor voltage v _Lo and the filter inductor current i _{Lo according to an} embodiment of the present invention.

The twenty-fourth embodiment is a measured waveform diagram of the filter capacitor voltage v _Co and the filter capacitor current i _{Co according to} the embodiment of the present invention.

The twenty-fifth figure is a measured waveform diagram of the output voltage v _o and the output current i _{o according to an} embodiment of the present invention.

1‧‧‧Resonance slot

2‧‧‧Bridge rectifier

3‧‧‧Low-pass filter

V _dc ‧‧‧ input power

V _gs ‧‧‧ square wave drive voltage

I _dc ‧‧‧ input current

L _f ‧‧‧ Choke inductor

v _Lf ‧‧‧ Choke inductor voltage

i _Lf ‧‧‧扼 inductor current

D _s ‧‧‧ forward diode

v _Ds ‧‧‧ forward diode voltage

i _Ds ‧‧‧ forward diode current

S ‧‧‧Power switch

v _s ‧‧‧Power Switch Voltage

i _s ‧‧‧Power switch current

L _r ‧‧‧Resonance inductance

v _Lr ‧‧‧Resonance inductor voltage

i _Lr ‧‧‧Resonance inductor current

C _r ‧‧‧resonance capacitor

v _Cr ‧‧‧resonant capacitor voltage

i _Cr ‧‧‧resonant capacitor 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

v _a ‧‧‧Resonant input voltage

v _b ‧ ‧ ‧ resonance output voltage

i _b ‧‧‧Resonance output current

v _b ‧ ‧ ‧ rectified input voltage

v _c ‧‧‧Rectified output voltage

Claims (1)

A zero-current switching parallel load resonant converter mainly has an input power supply connected to a choke inductor series forward diode and a power switch, that is, a positive terminal of the input power supply is connected to the positive terminal of the choke inductor, and a choke inductor The negative terminal is connected to the anode of the forward diode, the cathode of the forward diode is connected to the drain of the power switch, and the source of the power switch is connected to the negative terminal of the input power supply, wherein the forward two-pole system is set as a fast recovery diode Or a Schottky diode, and then a set of resonant tanks in parallel with the forward diode and the power switch, the resonant tank is composed of a resonant inductor series resonant capacitor, that is, the positive end of the resonant inductor is connected to the forward diode The anode, the negative end of the resonant inductor is connected to the positive end of the resonant capacitor, the negative end of the resonant capacitor is connected to the source of the power switch, the resonant tank is connected in parallel with the bridge rectifier, and finally the low-pass filter and the load are connected in parallel; thus, using a single one The power switch can reduce its switching loss under zero current switching, and has the characteristics of flexible switching and boosting to improve the operating efficiency of the converter.