TW201103243A - Resonant power converter - Google Patents

Abstract

A resonant power converter including synchronous rectifiers adapted to operate with an overlapping conduction phase and a fixed frequency.

Description

201103243 VI. Description of the Invention: [Technical Field] The present invention relates to a spectral power converter for direct current (DC) power. [Prior Art] Resonant power converters are used for DC to DC power conversion because they can exhibit low power loss, reduce electromagnetic current emissions, and enable variable voltage switching (ZVS) operation. However, existing resonant power converters have limitations in terms of their power efficiency, whether for high load or low load conditions, exhibiting undesired output power characteristics and requiring high manufacturing costs. Irj don't have a high slot current at 70 full load, and therefore require large and expensive electronic components 'have significant electrical losses when the load is light, and when there is no electrical load At this time, a high voltage should be generated on the output diode. A parallel-loaded inductor_capacitor-capacitor (lcc) spectral converter has improved performance, but typically produces a high-voltage stress on its output voltage for low-voltage output (due to high-output continuous wave) Therefore, this may require phase detection to prevent undesired losses due to multiple resonances in the body due to the loss of resonance. - The efficiency of the power converter should be as high as possible while at the same time - minimizing the complexity and use of the components. The word is based on this need to solve the above problems, or at least provide one available 201103243

An alternative to V. SUMMARY OF THE INVENTION In accordance with the present invention, a resonant power converter is provided that includes a gated gain that is adapted to operate in an overlapping conductive phase. The present invention also provides a resonant power converter that provides a resonant power converter. Operating at a fixed frequency, comprising: a spectral circuit, wherein a resonant voltage at the fixed frequency is on a primary side of an isolation unit; and a round-out circuit, the second of which is located in the isolation unit The leveling side is coupled to the resonant circuit by the isolation unit, the output circuit including a switch for conducting electricity during the respective overlapping conductive phases, and for generating a DC voltage at an output of the converter. The present invention also provides a control unit for a synchronous rectification (four) resonant power converter operating at a fixed frequency, comprising: an Bayi sensor circuit for sensing; and The power control circuit, the synchronous rectifier, the circuit, etc. within the resonant power converter can control the local bits according to the sensed power. The synchronous rectifiers are controlled to have an overlapping conductive phase. The invention also provides a method for operating a fixed frequency resonant power converter. The 201103243 method has a wheel-synchronous rectifier, and the control includes the rectifiers for operating in overlapping conduction. Phase. [Embodiment] A plurality of preferred embodiments of the present invention will be described by way of example only and with reference to the accompanying drawings. An overlapping conductive phase power converter in the form of a fixed frequency inductor/capacitor (LC) resonant converter (or FFLC) 1GG, as shown in FIG. 1, having a primary side 1〇2, which has a Connected to one is "a spectral circuit as shown in the input power supply (not shown), and a primary side party, which has an output circuit connectable to an electrical load (not shown), and The primary and secondary sides are joined by an electrical transformer 1〇6 and controlled by a control unit 1 〇 8. The input supply can be connected to the primary side via a power factor correction (pFC) unit ιι〇 102 for correcting the power factor of the input power supply to provide an input supply in the form of a DC® stream (Vbus). The DC input supply can be derived by various techniques, such as power factor correction ( The PFC unit 110) 'either utilizes a bridge rectifier and a capacitive filter, or directly from a DC power source to provide the DC bus. The FFLC 100 is utilized on the primary side 1〇2 by the primary side m〇sfet (Gold oxygen half-field effect crystal The fixed resonant frequency generated by F4 and F5, the core, and the MOSFETs are driven at the fixed frequency fr. The primary side FETs (field effect transistors) F4 and F5 are strung across the DC bus bar. The primary side FETs F4, F5 are driven by the control unit 1〇8 using a primary control 201103243 transformer 112 at the fixed frequency fr, and the secondary winding of the primary control transformer is connected to the primary side. The gates of FETs F4, F5, as shown in Figure 1. The primary side FETs F4, F5 produce a fixed frequency waveform at their output circuit node Va, i.e., like a square wave or a sine wave, ie Figure 3A shows the Va- waveform. The resonant voltage at the circuit node, through a resonant tank circuit, produces a resonant "slot" current, as shown by the It-waveform in Figure 3B. The blocking capacitor cb, a resonant inductor Lr and a resonant capacitor cr' are connected in series between the source and the drain of the primary side FET F5. The control circuit 108 can be disposed on the primary side or the secondary side (i.e., as shown in Figures 1 and 4-8). The control circuit 1 8 is consuming on the other side by means of an isolating device (such as the transformer 112, i.e. as shown in Figures 1 and 4 to 8). The secondary side 104 is connected in parallel to the resonant capacitor Cr by the transformer 1〇6, while the impedance of the secondary side 104 is dynamically controlled by the secondary side m〇SF]Bt FI, F2, and is controlled by the control unit 〇8 electrically controls these feTs. The secondary side MOSFETs F1, F2 are switched between the on and off states, i.e., as shown in Figs. 3D and 3E, so that they can be cycled in four states, i.e., as shown in FIG. The secondary side M 〇 SFETs FI, F2 are respectively connected in series to the secondary windings of the transformer 丨〇 6 which are individually tapped to the positive and negative voltages. A plurality of diodes are respectively connected in parallel to the secondary side MOSFETs F1, F2, and their anodes are connected to the terminals of the secondary side MOSFETs Fb and F2. The vibration frequencies fr are set by the resonant elements 1 and Cr. The control unit 108 can ensure that the converter has a 50% duty cycle, and is 201103243 at the natural resonant frequency of the "slot Thunder" circuit as shown in FIG. 3B, and τ^ η ''. Like sinusoidal slot current it. After the conversion thin film is used, the operation cycle is performed in order to facilitate the switching of the pirate system to the resonance cycle: the voltage switching 'the selected timing is arranged two = thus the slots of the primary side FETs F4, F5 Circuit = L: The central power in the f-slot circuit... The slot is determined to be switched when it is zero, so the frequency of the current It is as shown in Figure 3B. The spectral capacitor c is determined by the continuation of the thunder and the periodic Ray 1. Slot electricity "t is charged for generation - week

The gain voltage vc' is as shown in Fig. 3C - F1, μ total gate r. The # secondary side FET voltage Λ: at the capacitor voltage, is switched so that when the capacitor. For the material (4); this is called "zero voltage cut and can advantageously make the secondary side FET F1, F2 $ & right #t Μ + # η gentleman, 1 ^ ^ 旎 efficient switching and Low voltage stress. The secondary side FETs FI, F2 = a converter program _ under the control of the control unit 108, the program contains - a repetitive four = type loop 'that is shown in Figure 2 In the first mode (step 2〇2), the resonant capacitor voltage Vc driven by the 电 电 IL IL IL 会 会 会 会 会 会 会 会 会 会 会 会 会 FET FET FET FET FET FET FET That is, at point 3〇2 of Figure 3C. The first mode FET F2 is also turned on, and thus the two secondary sides fet f, F2 overlap in their conductive phase; however, when The resonant capacitor voltage proportional to the voltage across the two secondary side FETs FI, F2, equal to zero

The temple is so "Hai." The white vibrating valley II Cr is a "short circuit", and thus the cell current L increases linearly at this phase. The value of the f-vibration inductor ^ is k疋 such that the slot current it is minimized for losses. $ fflc i 〇〇 201103243 will remain in the first mode - the segment is set by the circuit, that is, if Tl has the entire private length of the control segment. 1 having the total time & % to the range between the Cong - is initiated by the control unit 108 and is followed by the second mode (step ^ ϋΤΛ _ $ # ^, the bribe F2 is closed, thereby A voltage can occur across (four) ° r, and thus the resonant capacitor vc is operated in a -spectral mode, that is, followed by a similar half-wave sine, P in Figure 3C, at points 3〇4 and 3. Between the 〇6. In response to the snubber capacitor voltage V on the primary side, the transformer 106 generates a primary side voltage across the FETs F1, F2, thereby generating an output voltage, £ and The output-pole load current Id' is the one between points 3〇8 and (4) in Figure 3F (corresponding to points 304 and 3〇6 of vc). This second mode will be maintained, straight: the resonance The capacitor voltage vc is negatively charged due to the negative phase of the tank current It (that is, the tank current It falls below zero at the point 312 and 314 in FIG. 3B). Zero. _ after the second mode, that is, by the control. Single A 1G8 - the second mode (step 2G6), wherein the FETF2 is at point 316 Turned on (as shown in Figure 3D and corresponding to point 〇 and 31 〇), and thus the voltage across the resonant capacitor is again shorted to zero. The third mode is similar to the = ,, except The resonant capacitor is charged by a slot electrode It flowing in an opposite direction. The third mode is maintained by the control unit (10) for a period τ3 which is equal to T (i.e., as to the shoulder of the overall period). After the third mode, the control unit 108 activates a fourth mode 201103243 (step 208), wherein the FET F2 switches off and the FET F1 remains on. This fourth mode is similar to the second mode. In addition to the resonant capacitor voltage

Vc is outside the reversal' and thus the secondary side of the transformer 1 〇6 will be connected to the load through the fet F2' instead of the FET F1, thereby generating a load current during the second mode. A second load current Id pulse is generated in the same direction (not shown in Figure 3F), i.e., dc power is generated for the load. After the 5th fourth mode, that is, the first mode is activated by the control unit 108, the output current id of the name FFLC 1 是 is generated by a series of pulses, and the pulses are in the second mode and The fourth mode occurs during the process, and the length of the period of the positive pulse is controlled by the control unit 1〇8 by controlling the length of the second mode and the fourth mode. Output current L current pulses corresponding to the second and fourth modes are periods of zero load current corresponding to the first and third modes, that is, overlapping conduction between the secondary side FETs F1, F2 The process of phase, is divided. Therefore, the control unit 108 can control the long-term average of the output current by controlling the lengths of the periods of the first, second, third, and fourth modes; this long-term ten-average voltage control method is similar to borrowing Pulse width modulation (PWM) for output power control.

The first == TC-1G8 generates a simple periodic control signal to cyclically operate the secondary side FETs between the F first and fourth modes: two: switching the primary side coffee to generate The periodic electricity house signal of the spectrum θ" circuit. The control unit A has just received an output voltage signal from the 10 201103243 secondary output node 114 (this represents the output voltage Vout). The control unit 〇8 can utilize the current transformer TCIA_B to sense the current through the Cr, that is, as shown in FIG. 7, or utilize a voltage sensing circuit 802 and an electronic amplifier/filter circuit 8〇4. The resonant voltage signal (which represents the tank current It) is sensed by sensing the voltage across the secondary side FETs F2, F1, as shown in FIG. The voltage sensing circuit 802 includes a resonant clamp (ciampi%) capacitor on each of the secondary side FETs F2, F2, and a terminal of each of the secondary side FETs F?, F2 is connected to the amplifier/filter The resistor of circuit 804. The resonant voltage signal is used by the control unit 108 to predict the zero voltage switching (ZVS) time of the secondary side FETs F1, F2. During the second mode, any excess energy stored in a secondary winding overflow "stray" inductance is routed through the clamping circuit 4〇2 to the output of the FFLC 100. Shown in it. The clamping circuit 402 includes clamped diodes m, D2 and a clamp m〇sfetf3 (which may be a P or N channel)' and provides an "active clamp": stored in the stray inductance The energy will be on the secondary side FETs f 丨, F2 is off 亦 'also V before the end of the modulo < and just before the end of the third mode, first by turning on the clamp FETF3 Clamping to the output, thus preventing the collapse of the corresponding secondary side FET, i.e., fi or f2, temporarily. 4 active clamp holding for lower electricity $ components can be applied to the secondary side FETF1, F2, these losses will be less, and resulting in less material loss 4 other, any stored in the secondary winding Excessive energy in the line-sink "stray" inductance can be controlled by a resonant clamp circuit as shown in Figure 10, 201103243. This circuit contains additional clamp capacitors 502A, 502B that span the configuration of each of the secondary side FETs F1, μ and form part of the overall resonant capacitor Cr. During the overlapping conductive phase 'that is, during the first mode and the third mode', the resonant tank current It is only the FFLC 100 during the first, second, fourth, and fourth modes. A small percentage of the overall output current. This advantageously provides a high degree of power efficiency within the FFLC 丨00. The control unit 108 includes a digital signal processor that is pre-designed to control the FFLC 100. The modulation commands for the primary and secondary sides F4, F5, FI, F2 are generated by the control unit 〇8 based on a digital control program stored on the DSP. The digital control program provides circuit calibration for slight variability in the value of electronic components, such as FFLC 100 operation for consistency, regardless of component values, such as resonant inductor Lr and resonant resistor rc. The slight variability of the chosen value is how it is. When the FFLC 100 is operated at the fixed or set frequency g, the magnetic elements including the resonant inductor Lr and the resonant capacitor g need only be provided by a physical device, and the physical devices can be Optimized to operate at this particular frequency fr, and thus more robust and/or less expensive than components optimized for a wider range of operating frequencies. The operating frequency is selected based on the final application of the FFLC 100 and the overall power system environment. In general, the resonant frequency is optimized over a range of up to 700 kHz. The resonant frequency fr can be increased to a 12 201103243. The leakage inductance of the transformer 106 can replace the frequency of the series of resonant inductors Lr; this high frequency FFLC 100 is incorporated into an advanced magnetically optimized package. In this case 'this frequency is usually optimized from 1 MHz to 2 MHz. The spectral conversion in the 6 FFLC 100 offers several advantages, including zero voltage switching (zvs), which results in low levels of electromagnetic interference (EMI) and thus easy electromagnetic compatibility (EMC) requirements. For high frequency operation, while at the same time streamlined magnetic design combined with high power efficiency and high power density. The FFLC 100 can be used in applications with power requirements ranging from 5 watts to 5 kW. The FFLC 100 can be controlled by the control unit 1 8 to operate in a "bum" mode, whereby the FFLC1GG can be reduced when the electrical load is small, that is, when the load draws a low amount of current. Power loss within. The control unit S108 controls the primary side FETs F4, F5 in the "surge" mode, wherein the pulse at the primary price "02 falls according to the output power, thereby missing the loop in the waveform shown in FIG. The town has a lower output and produces a lower output power. This "sudden dog wave" type, or other pulse thinning technique, can be used for low currents in electrical loads. · ^ 战者 for the more efficient operation of the brother and the vertical side in a replacement of the #古·+,, ’, ~ central distribution configuration, as shown in Figure 9. The mouse is configured for the press-full bridge. The FFLC 1〇〇 has a parallel negative cut, that is, the secondary side color 201103243 output circuit load is connected in parallel to the resonant capacitor cr. In an alternative fflc, the secondary side can be loaded in series with the resonant tank circuit, i.e., the transformer 106 is coupled in series with the resonant elements Lr and cf. The components in the FFLC 1 can withstand low voltage stresses. The secondary diode current Id has no multiple resonances. The secondary diode current Id is output by the inductor, that is, provided by the output inductor L〇ut, and is low. This active clamp circuit limits high current spikes. The primary side tank current is 80% of full load with little or no load, and this results in lower power losses than conventional circuits used for this load condition. The capacitive component "C〇ut" is used for the "overall" output capacitor and is necessary for feedback loop stability and chopping voltage reduction. This would require a smaller inductor than a non-fixed-frequency power converter—that is, the inductor can be a parallel-load variable-frequency power converter with a non-fixed, or variable, resonant frequency. Μ%. The overlapping conductive phase, i.e., in the first mode and the third mode, can accommodate a slight timing error, i.e., flashing, etc., without significantly altering the characteristics of the output diode current Id. The intersections of the secondary side synchronous rectifiers F1 and F2 are electrically conductive, and the output power of one turn is continuous.

The conductive phase is also available for control of the output and flexibility of the FFLc 1 。. Each cycle (the ratio 'in which there is an overlapping conductive phase to it, the sum of the second mode, can be from about 〇% to about 4〇0/〇R from the output power of the FFLC 100. If control is needed' then The overlap can be extended to 1 〇〇 0 / 〇. 201103243 Those skilled in the art will be able to modify the present invention without the use of the present invention as described herein with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a circuit diagram of an overlapping conductive phase power converter; FIG. 2 is a flow chart of a cutting program executed by the overlapping conductive phase power converter; Figure 4 is a circuit diagram of a converter with an active clamp; Figure 5 is a circuit diagram of a converter with a resonant clamp circuit; Figure 6 is a circuit diagram with a rectifier Figure 7 is a circuit diagram of a converter having a full-bridge configuration; Figure 7 is a circuit diagram of a converter having a current transformer for sensing the current of the slot; Figure 8 is a circuit having a voltage sensing circuit on the secondary side For sensing the slot Circuit diagram of the current converter; and Figure 9 is a circuit diagram of a converter with a synchronous rectifier and a full bridge configuration. [Main component symbol description] 100 Fixed frequency inductor-capacitor (LC) resonant converter (FFLC) 102 Primary side 104 Secondary side 15 201103243 106 Transformer 108 Control circuit 110 Power factor correction (PFC) unit 112 Primary control transformer 114 Secondary output node 200 Converter processing program flow chart 202~206 Multiple steps 302~ of converter processing program 316 point 402 clamp circuit 502A ' 502B clamp capacitor 800 full bridge configuration 802 voltage sensing circuit 804 amplifier / filter circuit cb blocking capacitor C 〇 Ut output capacitor cr resonant capacitor D1, D2 box · bit diode

Id load current

It Slot current L〇ut Output inductor L r Vibration inductor TCIA, TCIB Current transformer va Central voltage ^ Bus DC bus supply DC input 16 201103243

Vc capacitor voltage V〇ut output voltage FI, F2 secondary side FET F3 clamp FET F4, F5 primary side F E T 17

Claims (1)

201103243 VII. Patent application scope: 1. A resonant power converter, the converter operates at a fixed frequency, comprising: a spectral oscillator circuit, wherein the primary side of the isolation unit has a fixed frequency Resonant voltage; and 3: an output circuit 'which is located on the secondary side of the isolation unit and is consumed by the isolation unit to the snubber circuit, the output circuit containing conductive during the individual overlapping conductive phases a switch and for generating a DC voltage at an output of the converter. 2. The spectral power converter of claim i, wherein switching the switches is synchronized to the resonant voltage and when the voltage across one of the switches is substantially zero Switch. 3. If you apply for a patent scope! The spectral power converter of the item, comprising a control unit for controlling the switches. 4. The spectral power converter of claim 3, wherein the early twist is on the secondary side of the early turn and is coupled to the primary side by an isolation device. The resonance unit as described in claim 3 of the patent application is attached to the secondary side, and is controlled by a control isolation device to be coupled to the secondary side. Patent No. 4 or 5 Representing the resonant power converter, 〃中. The control isolating device is a control transformer. 7·If you apply for the scope of the patent range 3 to 6, the 哕捡 哕捡 丨 叮 》 》 》 》 》 》 》 》 》 》 》 1) Receive an 18 201103243 output voltage signal indicating the output voltage of the converter to adjust the overlap of the conductive phases. 8. As described in any of claims 3 to 7: resonant power conversion And causing the control unit to receive-representing the vibrating (four) vibrating signals, thereby controlling the switches in synchronization with the resonant voltage. 9. Resolving the resonant power conversion according to the patent application scope Test, wherein the control unit is sensed in the spectrum The current in the oscillating circuit is received to receive the stimuli voltage signal. 1 〇 · The resonant power converter according to claim 9 of the patent application, the emperor = the current is connected in series to the resonant circuit. The power converter of claim 4, wherein: the second dust sensor is configured to transmit the spectrum signal to the signal by sensing a voltage across the switches. control unit. _ ° month. The resonant power converter of claim 11 wherein the middle side voltage sensor comprises a booster filter for each. The sensor circuit of the mother knife is replaced by a sensor circuit and the converter of the third embodiment of the invention, as described in the fourth section of the converter. j early...-digital signal processor for control 14. For example, the U-term of the U.S. patent application scope, the white-magnet power of the project is connected in parallel with the spectroscopic circuit. For example, the patent range U 13 converter, wherein the 5 self-vibrating power described in the rim item is connected in series to the resonant circuit by the heart*. The circuit is as follows: A resonant power 19 201103243 converter according to any of the preceding claims, wherein the switches are arranged in a central tap configuration. 17· Resonance as described in the scope of claims -15 to 15 A power converter, wherein the switches are arranged in a full-bridge configuration. 18) The resonant power converter of the invention, wherein the resonant circuit comprises a resonant inductor And - the resonant capacitor number. 19. The damper power converter according to claim 18, wherein the resonant inductor and the resonant capacitor are connected in parallel. 2〇. The spectral vibration described in claim 18 A power converter, wherein the resonant inductor and the resonant capacitor are connected in series. 21. The resonant power conversion benefit according to any one of claims 1 to 2, wherein the spectral stimuli The cut state is provided by the overflow of the isolation unit. The resonant power converter of any of the above-mentioned items, wherein the resonant circuit comprises a blocking capacitor. The magnetic power converter according to any one of the preceding claims, The method includes a clamp circuit for discharging the stored amount in a stray electric current α of the secondary side of the isolation unit to the round of the converter. 24. The hunting vibration power converter described in the item, the clamp circuit is a Φ 饬 a, f active citrus position, which contains a plurality of clamp diodes, each of which is cut by a clamp 51 | V, a terminal connected to each switch by a knife changer; 5 the output. %, and 25. The resonant power converter according to claim 23, wherein the clamp circuit is a nucleus a ^ Passive citrus, which contains a clamp capacitor across each switch 20 201103243. /6. For the benefit of the above mentioned in the patent range, the switches contain two poles The parallel connection of the body can be cut as described in the above-mentioned items. The Wei power conversion is the transformer, and on the primary side there is - primary, 尧 line and there is - secondary winding on the secondary side. Change 2: Patent scope - The resonant power transfer, -, "4 conductive phase overlaps the period of the resonant frequency from zero to forty percent. 至29· As before the patent application scope] In the resonant power conversion state, the DC output is variable. 30. A four-vibration power conversion, which includes a synchronous rectifier, which is adapted to operate in an overlapping conductive phase and a fixed frequency. a control unit 'this single (four), for - a resonant power with a synchronous rectifier operating at a fixed frequency, "-sensor circuit, which can sense the power of the spectrum ==; and control A circuit such as a circuit can control the equivalent v-stolen according to the sensed power, wherein the synchronous rectifiers are controlled to have an overlapping conductive phase. 32. A method of operating a fixed frequency resonant power converter having an output synchronous rectifier' comprising controlling the rectifiers to operate in an overlapping conductive phase. twenty one