TWI262646B - High-efficiency bidirectional converter for power sources with great voltage diversity - Google Patents

Abstract

The aim of this invention focuses on the development of a high-efficiency bidirectional converter for power sources with great voltage diversity. In traditional bidirectional converters, the circuit topology with transformer form is the common usual. Moreover, the soft-switching techniques including zero-voltage-switching (ZVS) or zero-current-switching (ZCS) are usually used for alleviating the corresponding switching losses. However, there are four and upward power semiconductor switches in these circuit schemes. By this way, it will result in the increase of production cost, and the degeneration of conversion efficiency. The coupled-inductor bidirectional scheme in the proposed converter only adopts three power semiconductor switches to accomplish the objective of bidirectional current control. Under the situation of non-isolation circuit topology, it still possesses the protection of electric safety for operators. Due to the characteristics of high step-up and step-down ratio, the battery module with low voltage could be injected into a high-voltage dc bus for the later utilization, e.g., high-voltage load, front-end of inverter. Since the techniques of voltage clamping, synchronous rectification and soft switching are manipulated in this circuit topology, and the corresponding device specifications are adequately performed, it can achieve the goal of high-efficiency bidirectional power conversion for power sources with great voltage diversity.

Description

1262646 IX. Description of the Invention: TECHNICAL FIELD The technical field of the present invention includes the fields of power electronics, DC/DC converter technology, and energy technology. Although the present invention covers a wide range of technical fields, it mainly lies in The battery is used as an auxiliary power supply system to boost the battery power to a DC high voltage circuit system (or bus bar) or to reverse the # battery to provide the power required for bus emergency or capacity regulation. [Prior Art] a Due to the lack of energy caused by the oil crisis, cleanliness has been developed as an important issue in the world. The application of clean energy (four) systems and general batteries as auxiliary power systems can effectively reduce the backup and installation of clean energy, thereby reducing system acquisition and power supply costs. ^ Bay Power Supply Stable 'There will be fewer motor stops, and the status of conventional batteries' does not emphasize charging speed and efficiency. At present, the design of the building, to the location of the demand, the continuous power system is only available for power outages: oil:: "The short time of the machine parallel. However, the newly listed oil and electricity mixed sales in Asia to use its fuel-saving effect will be temporarily Use battery power to match the engine;: = read and quickly increase the efficiency of the two-way converter is the necessary power;; strong and good efficiency 'so it is used to expand the power storage in series 2 力 force = split. - General design The households 'avoid the technical problems and the disadvantages of the high boost ratio. The sequelae of the battery series is very important. The capacity and life of each battery are not - as long as there is a 1262646 failure, it will inevitably cause a power interruption. On the other hand, in order to consider the battery capacity balance problem, all series batteries must be replaced at the same time, and the same brand should be used as much as possible so that the battery capacity can be matched. Basically, from the power-voltage characteristic curve of the battery, parallel There is no matching problem with the battery pack, and the number can be increased or decreased arbitrarily, eliminating the problem of fault repair and battery management. This parallel combination of the low voltage power supply, high efficiency with high differential pressure than the bidirectional inverter its importance is even more evident.

Conventional two-way converters, such as references [1]-[1〇], are listed in Table 1 for their voltage specifications, capacity, efficiency, circuit architecture, and advantages and disadvantages. Table 1, comparison of conventional two-way converter technology

References Low Voltage Side Voltage High Voltage Side Voltage Output Capacity Maximum Conversion Efficiency Circuit Architecture Advantages and Disadvantages Comparison [1] [2] [3] [43 [5] [6] [7] [8] [9] [10]

24V

48V

100W 94% Half-Bridge Transformer Advantages Disadvantages

12V

5V

50V

36V

48V

24V

36V

10V

80V 50V

380V

9V

360V

70V

72V

24V

340V

288V

100V

1.6kW

20W

200W

120W

168W

60W

800W

1.6kW

200W 92% Half-bridge transformer boost 85% step-down 80% Advantages and disadvantages 4 faint Wh Capacitor charging type lacking k Light load efficiency can not be applied to heavy-duty phase shift control, with flexible switching frequency, turbid high architecture is simple, no Inductor switch is required to operate in the active area, low efficiency, synchronous rectification, switching boost, 91%, step-down 87%, 91% inductance + half-bridge transformer inductance + full-bridge transformer, not high, 93%, reverse 94%

Inspect the table-to-the-technical comparison. Part A is mostly transformer type ^62646. The power semiconductor switching components used are four to nine. Although some use zero-voltage or zero-current flexible switching technology, the current flows through too many switches. 'The loss of switching and conduction will be greatly improved. Another problem is that the transformer is not suitable for accepting a wide range of voltage changes. The reason is that the variable excitation current will easily saturate the core, and the transformer must withstand the full transmission power. The core capacity must be increased. If the above problem can be overcome, it is expected to be reduced. Cost and increase conversion efficiency. Remarks: References [1] DH Xu? CH Zhao, and HF Fan, UA PWM plus phase-shift control bidirectional DC-DC converter; 1 2 3 IEEE Trans. Power Electron., vol. 19? pp. 666-675, 2004.

[2] F·Z· Peng, H. Li, GJ Su, and J. S. Lawler, “A new ZVS bidirectional DC-DC converter for fuel cell and battery application; 4 IEEE Trans, Power Electron,, vol. 19 Pp. 54-65, 2004. 8 1 HSH Chung, W. C. Chow, S. Y. R. Hui, and S. T. S. Lee, “Development of a switched-capacitor DC-DC converter with bidirectional Power flow/5 6 IEEE Trans. Circuits Syst, vol. 47, pp. 1383-1389, 2000. 2 M. Jain, M. Daniele, and P. K. Jain, “A bidirectional DC-DC converter topology for low power Application,” vol. 15, pp. 595-606, 2000. 3 H. L· Chan, K· W. E· Cheng, and D· Sutanto, “Bidirectional phase-shifted DC-DC converter,” Lei/m* ·, vol. 35, pp. 523-524, 1999. 4 HL Chan, K· WE Cheng, and D· Sutanto, “ZCS-ZVS bi-directional phase-shifted DC-DC converter with extended load ranged IEE Proc. Electr Power Appl, vol. 150, pp. 269-277, 2003. 5 G. Chen, Y·S· Lee, S. Y. R. Hui, D. H· Xu, and Y· S_ Wang, “Actively clamped Bidirectio Nal flyback converter?!>, IEEE Trans. Ind. Electron., vol. 47? pp. 770-779, 2000. 6 CY Inaba, Y. Konishi, and M. Nakaoka, "High frequency PWM controlled step-up chopper Type DC-DC power converters with reduced peak switch voltage stress;7 IEE Proc. Electr. Power Appl, vol. 151? pp. 47-52, 2004. 7 K. Wang, C. Y· Lin, L· Zhu, D Qu, FC Lee, and J. S. Lai, "Bi-directional 1262646 DC to DC converters for fuel cell systems/5 in Proc. IEEE Workshop Power Electron. Transport, 1998, pp. 47-51.

[10] Υ·M. Chen, Y·C. Liu, and F. Y· Wu, “Multi_input DC/DC converter based on the multiwinding transformer for renewable energy applications^ IEEE Trans. Ind. Appl, vol. 38? pp 1096-1104, 2002. The high efficiency high-voltage differential ratio bidirectional converter of the present invention utilizes a bidirectional architecture of coupled inductors to perform dual internal current control using only three switches, and the structure has high rise and fall ratio characteristics. Therefore, the high-voltage busbar can be incorporated into the high-voltage busbar for use in the high-voltage load of the rear stage or the front end of the inverter. The switching technology of the inverter is fully utilized by voltage clamping, synchronous rectification and zero voltage and zero current. The component specification makes the device have the characteristics of high buck-boost ratio, low switching loss and low conduction loss, and can achieve high efficiency and high-pressure difference ratio bidirectional commutation. [Invention] The high-efficiency high-pressure difference ratio bidirectional disclosed by the present invention The structure of the converter, as shown in Fig. 1, includes a low voltage circuit 1〇1: consisting of a low voltage switch & and an inductor 7; the secondary side winding core, with a low voltage switch & Passing through, storing or releasing the coupled inductor is the energy of the primary winding b; an intermediate voltage circuit 102: consisting of the coupled inductor 卩 secondary winding core and a medium voltage capacitor ^ between the low voltage circuit 101 and the high voltage circuit Between 1 and 4, mainly using medium voltage capacitor A to increase the boost ratio or to withstand a part of the voltage when stepping down; a clamping circuit 103: by a clamped inductor & a clamped capacitor & a first clamped one The pole body, a second clamp diode/3⁄4 and a third clamp diode D3x are mainly used to absorb the leakage inductance energy of the coupled inductor, protect the low voltage switch & 1262646 and release the absorbed amount to the output end. ; - high voltage circuit 104 · · by - high β & & , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , A step-down circuit 105 is composed of a step-down switch & a step-down inductor core and a step-down diode 2, and is responsible for discharging the discharge circuit of the medium voltage capacitor & The low-voltage circuit 1 〇 1 and the voltage-suppressing circuit 1 〇 4 represent two very large DC voltages, respectively, which are defined as power and load and are interchangeable. In other words, if the power source is in the high voltage circuit 104, the load is the low voltage circuit 101. The load can be a DC device or a state of charge battery. Conversely, after the low voltage circuit 101 represents the boosting, the power supply energy is boosted to the high voltage circuit 104 to provide a high voltage DC bus load, which may be a battery, or a fuel cell, a wind power generator, or a solar power source. DC power generation unit for clean energy. All in all, the unit has two functions: boost and drop. Body pressure: When the low-voltage switch & is turned on, the low-voltage circuit 101 is the power supply, and the coupled-inductor primary-side winding k is in a charged state, while passing through the coupled inductor 7; the secondary-side winding core, combined with the clamped capacitor 〇1 for the medium-voltage capacitor & Charging, when the low-voltage switch is turned off, the coupling inductance 7; the leakage inductance energy is absorbed by the clamp capacitor q; when the leakage inductance is greatly reduced, the coupling inductance is on both sides. The winding combines the low-voltage power supply voltage ^ and the medium-voltage capacitor Q, The power of the south voltage circuit 104 is supplied via a high voltage switch. Buck: high voltage switch & Turn on, 10 1262646, South ink circuit 1〇4 is the power supply, high voltage circuit 104 is connected to the circuit 102 and low voltage circuit 101; "The circuit of the same V-shape & is passed from its secondary winding & to the load of the low voltage circuit 101. At this time, the medium voltage capacitor c2 is also provided by the low voltage switch 4 and the buck switch *S2. Through the light-inductive inductance (secondary winding ^ and the step-down inductor A to supply the load of the low-voltage circuit 101. , Ben Ming's "鬲 efficiency high-voltage difference ratio bidirectional converter" has two functions of DC step-down and DC step-up. Therefore, there are two sets of circuit timing and working mode. 'The following will be divided into two parts, A and B. The working principle is detailed. To simplify the circuit analysis, all switching elements and diodes have a negated voltage drop. In addition, for the sake of simplicity Understand that the proper nouns are not too long, the circuit attribution figure number (such as ... circuit 1〇1) is omitted, and the direct description of the associated schema can be understood. A. The step-down part of the south efficiency high-pressure difference is lower than the bidirectional converter Working part of the voltage part circuit The circuit timing shown in Figure 2 and the circuit operation mode in Figure 3, the following analysis will be described with reference to the two figures. The high-efficiency high-voltage difference ratio bidirectional converter equivalent circuit shown in Figure 绘制 is shown in Figure 2 (a As shown in the figure, since the circuit has two operating modes of boosting and bucking, in order to clearly indicate the positive current flow of the inductor current, the definitions of positive and negative currents of all the figures of the present invention will be unified according to FIG. 2(a). In addition, for the convenience of power supply and load application, Figure 2 high voltage 11 1262646 - side shunt capacitor analog power supply or load effect, low voltage side battery, both power and load function. However, because the device has two-way energy transfer function ' The application power supply or load type is not limited to this. Mode 1: Time [6 ~ high voltage switch & turn on for a period of time between 〖=& when 'high' switch & turn on for a period of time, the switch 'pass current from south The voltage circuit passes through the medium voltage circuit, the voltage capacitor q and the | horse combined inductor 7; the secondary side winding &, and finally the low voltage circuit coupled inductor i primary side winding Zp flows out to the low voltage circuit end. The f-inductor C, the secondary side winding core and the heart are equivalent to two inductors connected in series, and wound in the same iron powder core. Let the inductance 7; the primary side winding b and the secondary side winding core The ratio is # Λ^/Λ^, the magnetizing inductance is 丄 and the leakage inductance is &, then the coupling factor is defined as k = LMAh+LM) (1) Since the coupled inductor adopts the sandwich winding method, the coil coupling effect is good. And the leakage inductance energy of the coupled inductor is small relative to the volume of the iron powder core. As long as the voltage clamping effect is achieved, the leakage energy is fully absorbed, and the influence on the system voltage is not high. In order to simplify the mathematical formula and facilitate the theoretical analysis, The coefficient of moxibustion is defined as 1. Since the inductance of the same iron powder core is proportional to the square of the turns, the right Z and zM2 represent the magnetizing inductance of one of the coupled inductors c and the secondary winding, respectively, and the relationship is LM1 ·· = M2 : W, so The magnetizing inductance of the coupled inductor in mode 1 is the series addition of the two inductors, which can be expressed as 1262646 LM={l^N)2Lm={\ + \IN)2LM2 (2) The average value of the excitation current in this mode/ZMv and excitation Current climb rate is

Ilmv II Pin IVh (3)

Lm^lm Idt-VH -vC2 - VL (4) If the coupling inductance 7; the coupling coefficient to the left is 1, then 1 ship = heart and _ / ^ 2 = 4. The power is supplied to the voltage of the high voltage circuit 13⁄4; ve2 represents the voltage of the medium voltage capacitor of 6:2, which can be regarded as a constant voltage because of the large capacitance value. When the power supplied from the input end of the high voltage circuit is constant, the high voltage switch flows through the average current as the product of the voltage plant of the high voltage circuit. Considering the high-pressure difference ratio and ignoring the loss, the ratio of the excitation average current to the low-voltage average current zZv is approximately equal to the step-down ratio (匕/heart), so the current 匕^ is much smaller than the current. In addition, it is known from equation (2) that the inductance value is proportional to the square of the number of turns, so that the two windings of the coupled inductor are excited in series, and the magnitude of the magnetizing inductance is higher than any one. After the voltage of the magnetizing inductance ^^ is deducted from the voltage ve2 and 匕, there is little left, plus the magnetizing inductance ZM amplifies the value of the magnetizing inductance of the independent winding of the light-inductive inductor, so the value of the suppression, which represents the current flowing through the high-voltage switch 4 The wave component can be effectively reduced. Therefore, the low average current and low chopping current waveforms naturally produce less conduction losses, such as the conduction loss of the MOSFET. Let and be the voltage of the coupled inductor first and second side windings and the heart, then the relationship between the two is (5)

VLS 丨VLP II N 1262646 - Therefore, the voltage core of the high voltage circuit can be expressed as 'V^^vls+Vlp+VlHN + 1)Vl^Vc2+Vl (6) In this mode, the face inductance 7;-, secondary side The winding core and the 々 are simultaneously excited, and the two winding currents are combined. The same direction is equal (also equal to and continues to rise, and is supplied to the output of the low-voltage circuit. In addition, the current b of the step-down circuit is provided by the step-down inductor Z2, which is supplied through the circuit of the reduced-discharge diode A, and discharged to the battery of the low-voltage circuit. Therefore, the electric current of the inductor is %=匕, and > the battery charging t flow is f. Furthermore, the low voltage switch ^ is observed to be in an off state, and its cross voltage is VDSl^yL+yLP (7) mode two: time [W2]; High voltage on_trigger signal cutoff moment high voltage switch & trigger signal cutoff instant (called), light combined inductance ^ both sides of the winding LP and the heart loses the excitation power provided by the high voltage switch 4, but due to the leakage inductance of the primary and secondary windings ^ and 々2 still have energy release, and the current does not change instantaneously in one method, so that the secondary side winding v current b passes through the buck diode/3⁄4 and IV疋 switch & flywheel diode path freewheel, but its value Gradually decrease. At this time, the switch has zero voltage at both ends, waiting for the next mode Zero Voltage Switching (ZVS). According to the law of flux incompetence, since the secondary side winding release current path (high voltage switch 4) has been interrupted, Storage of iron powder The energy in the core will only have one primary winding loop left, and its current will pass through the flywheel diode path of the low voltage switch & the release to the low side battery and gradually increase by 14 1262646. At this time, the switch is also zero voltage at both ends. Wait for the next mode to synchronously rectify conduction. Mode 3: Time [纟2~6]; Low-voltage switch and buck switch & Trigger signal turn-on moment The previous mode has formed a low-voltage switch & buck switch & flywheel diode Body conduction 'this mode starts to directly trigger conduction, component current characteristics, keep the previous state continuously changing. The former is synchronous rectification, and the high-inrush current for low-voltage circuits, the synchronous rectification technology can greatly reduce the conduction loss of the flywheel diode' The switch has zero voltage conduction and no switching loss. This mode stops at the coupled inductor 7; the secondary winding current is reduced to zero. Mode 4: Time 13⁄4~〖4]; Medium Voltage Capacitor (^ Discharge to Low Voltage Circuit This Mode Starting from the excitation energy by the inductor and the primary winding current, all released in the low-voltage circuit, the secondary winding current. From zero to positive, indicating medium voltage The capacitor & begins to discharge, the path is charged to the battery via the buck switch & buck inductor A to the low voltage circuit, and then returns to the polarity end of the secondary winding core through the flywheel of the low voltage switch. The step-down inductor A is in the state of energy storage, and its voltage 々2 can be expressed as VL2 = VC2 (8) At this time, the secondary side winding current b includes the excitation current and the induced current from the high voltage side ^ 'via the low voltage switch \ for the low voltage circuit When the battery is charged, the voltage is, if the primary winding current ignores the gap of the switch, the empty 1262646 white time (Lockout Time), so that the high voltage switch & duty cycle is printed with (6) 4, and the low voltage switch & and the buck switch & The duty cycle is the same as 1 3 (9) The step-down inductor 12 voltage vZ2 is between the three voltage sources of 匕, ~ and Vc2. The meaning of the existence is that the three voltage sources must be connected in series with a current source to form a loop. The pressure difference among them. Since the mode is low, the step-down inductor A voltage 々2 is equal to the battery voltage 低压 of the low-voltage circuit. According to the volt-second balance (v〇it_sec〇nd Balance), the mode four-time voltage μ can be obtained as VL2=1Ld3^l (1() Substituting the equation (1G) and the secondary winding voltage ~=7^ into equation (8) can be obtained vc2 = (#+i+d3/岣)fz (1)) This mode - the voltage of the human side winding vLp is equal to The battery voltage of the low-voltage circuit is ^, so it can be based on the volt-second balance (v〇lt_sec〇nd such as 丨(10)(3)), and the voltage of the available mode is VLP=VL^\i ^2). ), Equation (11) and the equation illusion into the equation, and let the step-down ratio be defined as Gn, then its value can be expressed as (13) 16 1 h N(l^d3) + \ Use equation (13) to draw different parameters When compared with #, its buck ratio ^^^ is related to the high voltage switch & duty cycle 4, as shown in Figure 4. It can be understood from Responsibility Week 1262646 Period 4, ^ ^, the deceleration ratio (representing the low voltage side can be adjusted by the highest voltage of the output 5Gri / condition 3 = 〇 position, the value can be expressed as follows: 3 (max )

^ ^ 7 occurs in the responsibility cycle d (Η) _ also represents high (four) off ^ maximum responsibility cycle. Observe Figure 4, less than the responsibility cycle area of '), the greater the duty cycle, the output voltage of the low-voltage circuit will rise 'but if it exceeds the 'called part, the output voltage of the low-voltage circuit is below β, anti-ik under & therefore exceed &The;_) part of the duty cycle will not be able to regulate the output voltage of the low voltage circuit. Equation (9) can be obtained by equation (7) to obtain the voltage across the end of the low-voltage switch 16 and the clamp capacitor ς voltage Vci VDS\ - VC1 - /(15) According to equation (15), it is the slope of the step-down ratio curve of Figure 4(4). . When the buck switch .3⁄4 current (4) is greater than the buck inductor current ^, the buck diode A is turned off and the second clamp diode is turned on to release the current of the clamp capacitor q / C1, at which time the high voltage switch 4 is The voltage is reduced from ^ to 4 -vL2+Fl. Mode 5: Time [~~匕]; Low-voltage switch & buck switch & trigger signal simultaneously cut off the current flowing through the buck switch & the current will charge the parasitic capacitance of the switch 'because v is still 3+ v, such as the voltage relationship of +Vd2=^, voltage ^ illusion on 17 1262646 幵 'the other two flows 〖L2 conduction, the step-down inductor 12 is continuous power according to equation (12) can be 'other voltages are bound to fall. First, k is turned on and the step-down diode must be turned on. Find the voltage across the two ends of the step-down diode A at the end of the mode cutoff, (16) VD2 ~ The maximum value of the duty cycle a has been limited according to equation (14), and the maximum value is substituted into equation (16). The pressure specification of the step-down diode a can be designed. According to Figure 4, most of them are between ορό·?, so the buck•diodeΖ2 can withstand the highest battery voltage of about three times the battery voltage, so it can be used low and low The Xiaoji diode. Secondly, the secondary side winding leakage inductance 'Ζ*2 and the clamped inductance hook must be kept continuous, and the conduction path must force the high-voltage switch & flywheel diode to conduct, because the step-down diode A is fast Xiaoji one pole, at this time with the high voltage switch & both voltage across the voltage clamped each other, a long cut, when the buck switch & cut off, the high voltage switch & claw wheel one pole is also turned on, At this time, the clamping inductor A releases the voltage to the high voltage 汾=匕-VC1, so the current k drops rapidly. Since the leakage inductance remains in the residual 爿b, the induced currents A and Ϊ·2 of the windings on both sides of the coupled inductor 4 cannot be cut off immediately, but fall rapidly. Mode 6: Time [匕~(6]; High-voltage switch & trigger signal conduction When the flywheel diode of the pressure switch 4 is turned on, the voltage across the switch is zero, and the trigger signal is turned on, and the waveform has zero. The effect of voltage switching. Since the current freewheeling mode of each component of the rain mode has reached the end, plus the high dust switch 4 gives the coupled inductor 7; the excitation path, the secondary winding core will accept 18 1262646 excitation, primary winding current b will gradually decrease. Due to the influence of the secondary side winding core excitation, the primary side winding non-polar point voltage is positive, the low side switch & flywheel diode is cut off, the primary side winding current ^ starts to the low voltage switch & parasitic capacitance Charging. Since the parasitic capacitance of the low-voltage switch & is larger than that of the general high-voltage switch, the required charging current is higher when the voltage across the two terminals rises, and the charging current includes h, condition 2, and G. After the current is released by the clamped inductor hook , the second clamp diode & cutoff, its reverse recovery current will flow back to the clamp inductor A, which will cause the voltage oscillation of the two, so the addition of the third clamp diode Dk can be effective The second clamp diode is the voltage of 3. When the voltage of the low voltage switch A is equal to the voltage of the clamp capacitor q, the mode ends. Mode 7: Time h~ The first clamp diode is the low voltage switch and the voltage is high. When the voltage of the capacitor q is clamped, the first clamped one pole is turned on, and the current previously charged to the parasitic capacitor is introduced into the clamped electric power. Since the capacitor has a large design capacity, the voltage has almost no wave, low voltage. The switch & cross-voltage is thus limited, and the path provided in mode 4 transmits energy to the low-voltage circuit. The voltage is as shown in equation (ls), and the private voltage is proportional to the duty cycle 4, so it can be used. The low I low-conductance notification loses the MOSFET switch. When the leakage inductance energy is released, the first clamping body Q is turned off, indicating that the induced currents 纟1 and 丨2 are reduced to zero, the coupled inductor 2; the primary side winding core and the heart The phase of the high-voltage circuit is also connected in series. 19 1262646 Β · Boost part of the efficiency of the voltage difference than the bi-directional converter step-up part of the circuit: in, as shown in Figure 5 and Figure 6 circuit timing and mode of operation. When the flow is processed, the step-down circuit components do not need to work, such as the buck inductor 12, the buck diode sentence, and the buck switch & the circuit operation mode of Fig. 6 shows the step-down circuit portion as a broken line. The following analysis will be explained with reference to the two figures. 杈 Type 1: Time ~ 6]; Low-voltage switch 4 is turned on for a period of time, the low-voltage switch 4 has been turned on for a period of time, coupled with the inductor 7; - the secondary side winding from the battery of the low-voltage circuit The current is excited, and the current ζ·Ιρ of the primary winding core is composed of the primary side induced current & and the exciting current. The primary side induced current 4 is derived from the secondary transformer induced current of the secondary transformer 4 from the ideal transformer. 2; and the excitation current 匕^丨 is generated by the excitation inductance, mainly stored when the low-voltage switch Α is turned on, and then transmitted to the secondary winding core when the low-voltage switch & At this time, the currents 46 of the two currents all flow through the low voltage switch A, wherein the secondary side winding As senses the polarity point to be a positive voltage, and the voltage v of the capacitor 〇1 is clamped in series, via the hanging inductor 4' and the low voltage switch 4 and the second The system diode forms 20 1262646 'ι loop, charging the medium voltage capacitor q. The front step-down part has a coupling coefficient b, the domain content and its value is 1. (4) The clamp inductor Ζι deliberately designs a small inductor whose current t is equal to the secondary side winding current 'belongs to a small current, and more because of the secondary winding The leakage sensation 2 affects and limits the current change rate, so the secondary side winding voltage 2 is almost negligible, so the voltage of the medium voltage capacitor VC2 can be calculated.

vC2=NVl+vci (17) U During this period, 'low-voltage switch & current' is equal to (5)·+ζ·2. Since the excitation charge stores energy for the inductor, the current gradually rises from small to small, and the slope of the waveform is positive 1 turn-on instant. The charging current c2 of the medium voltage capacitor c is the peak value of one cycle, and decreases as the capacitor voltage gradually rises. The current 丨2 is generated by the primary side induced current ^, and the relationship is /1=external, and the slope of the current 4 waveform is negative. Therefore, the current of the primary winding is 'the sum of the two and the sum of the two, and the slopes of the two waveforms are complementary, causing the low-voltage switch & during the conduction period, the current b approaches the square wave, and the primary winding current k plus two The secondary side induced current Μ high voltage small current) is equal to the low voltage switch & current, and its waveform is also close to the square wave. The square wave's electric grab wave opens > represents two points. · The first point, flowing through the low voltage switch ^ The current waveform has a low chopping component, and the switch conduction loss is proportional to the square of the current, assuming the same average current. The square sum of the square wave current is smaller than the square sum of the triangular wave currents, so the conduction loss of the low voltage switch caused by the square wave current is much lower than the high chopping current. The second point, the current ^ and the current both wave 21 1262646 shape slope is opposite 'can accept a lower magnetizing inductance, representing the light coupling inductance 7; the number of secondary windings b and the core capacity can be greatly reduced, _ secondary side group The copper loss and core loss caused by high current are also reduced simultaneously. Mode 2··Time Ui~Q]; low-voltage switch trigger signal wear-stop low-voltage switch & trigger signal is off at ί = ^, limited by the coupling inductance of a secondary side winding leakage energy release effect, coupling electric salt A _ ^ ^ winding current Lp and b ' freewheeling and charging the parasitic capacitance of the low-voltage switch, the voltage across the switch is ramped up, and the voltage across the high-turn switch ^ V is also starting to drop. This mode ends when the low voltage switch & voltage ν^ι is equal to the painful capacitor G voltage VC1.杈式二··Time [G~coupled inductor secondary winding current one turns to low voltage switch & voltage at both ends 1; melon 1 is higher than clamp capacitor q voltage, 1 first clamp diode / ^ conduction, right The clamp capacitor q is charged, absorbing the leakage energy of the primary side winding and the leakage energy. Since the capacitor is a high-capacity capacitor with high frequency, the current is quickly guided to the clamp. The voltage vcl can be regarded as a stable low chopping DC voltage to ensure that the switch can withstand the maximum value of the switch. In addition, the first clamp diode A:, the shell is f idle, the pass_pole body, and the withstand voltage specifications are the same. For low-voltage switch ^, so the low-shear / Xiao power consumption and low-on-voltage of the Xiaoji diode is the best choice. ' 〃 + view the nuclear circuit characteristics, if the magnetic flux is continuous, clamped. Cl is the output of the traditional boost converter (Boost Converter), which is 1262646, so the voltage of the clamp capacitor voltage vcl and the low voltage circuit is & VC1 = ^L + VLP = VDSl (18) due to the secondary winding core only There is a high-voltage induced current &, which is much smaller than the primary winding current ζ·ΖΡ, The leakage inductance energy of the secondary side winding is faster than that of the primary side winding. The leakage inductance of the primary side winding is due to the presence of a high current, and the release speed is slow, and the voltage of the complementary clamp capacitor is reduced by the mode one, the freewheeling time. Longer. The high-capacity clamp capacitor ς can fully absorb the energy of the leakage inductance of the primary winding. 'From Handan Electric Cheng Uj, when the mode is 丨卩, / when the caller is turned on, it is released to the medium voltage capacitor c2. The leakage inductance energy is clamped and boosted. The secondary side winding current b drops to zero at time 6 and the primary side is magnetic current / ^ ^ release energy, through the magnetic circuit to the secondary side, the current L slowly rises and flows out Polar point. The secondary side winding current L will force the ^ switch! The parasitic capacitance voltage, discharged to the high voltage circuit, gradually drops to zero and is guided by the flywheel diode of the high voltage switch 4. Mode::.called ~, 4]; high voltage switch 4 trigger signal conduction 咼 开关 开关 开关 开关 开关 开关 开关 开关 开关 开关 开关 开关 开关 开关 开关 开关 开关 开关 开关 开关 开关 开关 开关 开关 开关 开关 开关 开关 开关 开关 开关 开关 开关 开关 开关 开关 开关 开关 开关 开关 开关 开关 开关 开关 开关 开关 开关, the heart of the heart is said that the battery voltage of the day, -, % 〇 group voltage VLP, primary side winding voltage _ electric and medium voltage capacitor voltage", with low current type on the high voltage capacitor C f / c. The energy is Λ the law of magnetic flux immortality, the energy consumption in the leakage sense is k-kun light and inductance 7; still will learn

The duration of the period is one, - 々 婊 4 A - the side winding circuit provides current, - (5) 1262646 1 clamps the electric charge q charge, and the secondary side winding discharges current to the high voltage circuit. In the middle of mode four, the medium voltage capacitor c2 voltage ~2 drops due to continuous discharge, while the clamp capacitor C1 voltage rises for a long time, and the first clamped diode A reverses off. At this time, the secondary side winding current 仏 is equal to the secondary side winding current b, and this mode is ended. Mode five-day custodial [heart ~ 纟d, face inductance 7; equal winding on both sides of the current discharge to the high voltage circuit

Face inductance 7; when the winding currents on both sides are at current l, the energy I stored in the iron core is released in the two windings. At this time, the inductance is applied (the secondary winding core is at the non-polar point, the voltage is Positive, its value is VLS = Nvlp = dxNVL / (1 ~ dx) (i 9) At this time, the voltages Fz, v〆vC2 and vZtS are discharged to the high voltage circuit, using equations (17) to (19), high voltage The voltage of the circuit ^ can be calculated as follows:

= + VLP + VC2

+ V

LS (20)

Gv2--Vi

VL 2 + N \-dx (21) According to equation (21), as shown in Figure 7, the relationship between the boost ratio and the low-voltage switch & duty cycle 4 is shown in different turns ratios y, and with the conventional coupled inductor A comparison of the voltage gain of the circuit [Note - Conventional Coupled Inductor Circuit 24 1262646 . References: Q· Zhao, and F. C· Lee, “High-efficiency, high step-up DC-DC converters/5 IEEE Tran. Power Electronics, vol. 18, pp. 65-73, 2003]. If we substitute equation (18) into equation (20), we can get the low voltage switch & cross voltage VDS\ - + 2) (22) Observe the equation (22) ), the voltage core and the turns ratio of the high voltage circuit are fixed to the TV, and the voltage of the low voltage switch & is independent of the voltage of the low voltage circuit and the duty cycle 4 > therefore, the maximum voltage of the power semiconductor switching element can be ensured. As long as the input voltage is not higher than the low voltage switch & withstand voltage, the converter designed according to equation (22), combined with the original high voltage gain ratio characteristics, the low voltage circuit can accept high and low voltage wide range of varying voltage. High voltage switch & trigger signal can be Before the voltage switch & turn on, stop early and stop the synchronous rectification mode. Mode 6: Time [G~(〇]; Low-voltage switch & Trigger signal conduction moment | Low-voltage switch 5\纟纟=(5° conduction, due to the first The clamped diode is a low-voltage Schottky diode, and the low-voltage switch & turns on immediately and reverses. The coupled inductor 7; - the secondary winding leakage inductance 4 limits the current core rise slope, and flows to the secondary side winding leakage inductance The current b needs time to fall to zero, the two leakage currents are mutually clamped' and the first clamped diode is reversed without reverse recovery current, and the switch cannot be self-voltage circuit, medium voltage circuit and first clamp diode q, etc. Road • Controlling any current, naturally forming a zero current switch (Zer〇Current 25 1262646

Switching, ZCS) features. At this time, the circuit current still maintains the output side flow, but gradually decreases, so the circuit has a flexible switching characteristic when it is turned on, effectively reducing the switching loss. After the leakage energy is released at the end of this mode, the secondary side of the coupled inductor C is turned around, and the electric hunger w turns into the low-voltage switch & the small current is applied to the flywheel diode of the high-voltage switch, and the reverse recovery current is applied. Since the box inductance ^ cannot 3 = supply current to the secondary side winding current L, forcing the first clamped diode A and the third clamped diode to be simultaneously turned on, and the cutoff (four) shot 3 cross-hearted is equal to the high (four) way The voltage is 6. When clamping! Current / £1 is equal to the secondary winding core, the third clamping diode is turned off (4), switch 4 crosses the pressure, returns to kvcl, completes a switching cycle (Switching Cycle), and then - The situation. Next, it is used as (4) to return to the mode. In the present invention (4) riding pressure _ working mode, if:::: square ί' part of the component can be taken: generation or omission, still available rectifier wedge:: use the buck mode alone, The low-voltage switch X is only operated in the synchronous replacement of the Schottky diode of the conduction loss. If the single switch w/ is used, the step-down circuit can be omitted, due to the high generation. 3 In the synchronous rectification mode, the general diode can be used. January is to improve the prior art for domestic and foreign literature and custom circuits. 26 1262646 Principles and comparisons are as follows: 1. Less switches and simple structure. The high efficiency high-voltage difference ratio bidirectional converter of the present invention can realize the bidirectional energy transfer function by using only three switches, and the prior art requires at least four switches, which is not only simple in structure, but also has few components and low cost. 2. With high pressure difference ratio, low voltage power supply has high selectivity. The inverter of the present invention 4 can accept a voltage with a high difference between the two ends. In practice, the high-voltage circuit can provide the high-voltage DC power supply of the front-end of the inverter required for the AC electrical load, and the low-voltage circuit can be used with the 12V high-capacity battery. It is not necessary to connect multiple batteries in series, and directly change to parallel to avoid battery connection. Power management issues caused by the failure. 3. With voltage clamping and flexible switching, the conversion efficiency is high. The inverter of the present invention sufficiently introduces the characteristics of the low current on the high voltage side and the large current on the low voltage side, and clamps the highest voltage of the switching element, thereby making full use of the component benefits, including switching utilization, low conduction loss, and cost. Further, the inverter of the present invention uses the characteristics of the leakage inductance to achieve zero voltage switching and reduces the switching loss of the high frequency. Therefore, the number of switches is reduced and the loss of conduction and switching is suppressed, and the conversion efficiency is naturally improved. 4. All switches and diodes can achieve voltage clamping. The converter of the present invention has no problem of short-circuit current when the switch is turned on and the reverse high recovery current of the diode, and does not need to be equipped with a cushioning circuit. 5. In the boost function, the required voltage of the switch is independent of the input voltage. When the converter of the present invention is operated in the boosting mode, the voltage of the power semiconductor switch is only 27 1262646 with the ratio of the DC output voltage and the coupled inductor. This feature is more suitable for the power supply with a wide range of DC input voltage. The conversion device is applied, however, the necessary condition is that the DC input voltage source cannot be higher than the power semiconductor switch. 6. Although there is no electrical isolation, it still has electrical safety characteristics. According to the theoretical analysis of the buck-boost circuit in the manual, the low-voltage circuit is in an open state and there is no high voltage. In the event of a force-to-force factor, such as a component failure, a low-voltage condition occurs on the low-voltage side. However, due to the low-voltage characteristic of the low-voltage device, the switch v must be over-voltage breakdown and short-circuit current. It reduces the voltage of the low-voltage circuit-related components that the human body is relatively easy to contact. The short-circuit current is enough to quickly blow the fuse, and isolates the path of high-voltage conduction to the low-voltage circuit to ensure that the operator does not experience a power-sensitive accident when it contacts the low-voltage circuit. [Embodiment] ^ The specification of the high efficiency high-voltage difference ratio bidirectional converter design of the present invention is based on the high-voltage circuit ink F^OOV and the low-voltage circuit electric dust 匕=24γ: the verification of the two columns' consideration is AC 11 The front-end power supply of the 〇v inverter is generally calculated as DC 200V, and the standby power supply has the load as the primary battery =, and the two sets of DC 12V battery packs are commonly used in the industry. In the first step of the circuit design, the resistance ratio of the light-inductive inductor and the specification of the switching element are first determined. According to the voltage specification, %2=1/Qiaoguang 8.33 is the high voltage, the duty cycle name must be designed according to equation (14), and must meet the voltage regulation requirements of buck-boost bi-directional voltage gain, so use Figure 4 And Figure 7 乂 and compare, you can determine the turns ratio # = previous rise and fall two working methods have shown that the clamp capacitor 〇1 can absorb the leakage of the coupled inductor 28 1262646 ~ sense energy, its energy can pass through other paths Provided to the output, so the leakage inductance ratio can affect the range of voltage gain is limited. The coupled inductor used in the present invention can accept a high leakage inductance transformer, and is not limited to the use of a high coupling coefficient sandwich stacking method, using the conventional two Winding can be done separately. The coupling inductance of the present embodiment is a south-excited current double-winding transformer with a south air gap. The turns ratio is different, the voltage and current range are different, the number of turns on the low-voltage side is small, and the high-voltage side is opposite. Substituting the turns ratio into the step-down circuit shown in Figure 8, designing the high-voltage circuit voltage > ^=20〇ν, at different turns#, its low-voltage switching voltage 1/^, low-voltage circuit voltage ^ and high-voltage switch & responsibility cycle 4 relationship curve. According to this figure, when the voltage of the low-voltage circuit is zero, the low-voltage switch 4 is subjected to a voltage of up to 65V, so that a MOSFET component with a rated voltage of 80V can be selected. As for the buck switch & and the high voltage switch & the highest voltage is equal to the high voltage circuit voltage of 200V, so you can choose a MOSFET component with a rated voltage of 250V. In terms of diodes, the second clamp diode is the same as the voltage of 200V and the high voltage circuit voltage is 200V. The fast voltage diode with a rated voltage of 250V can be selected. The other two diodes are less than or equal to the voltage clamp effect. The voltage να of the capacitor is clamped, so a Schottky diode with low turn-on voltage and low reverse recovery can be used. The switching frequency of this embodiment is 100 kHz, and the detailed specifications are as follows:

VH : 200V VL : 24V 7; : Αν·#2=3Τ:6Τ ; ZP=14//H; 4=52"Η; moxibustion = 0.98 ; . core : EE-55 29 1262646 ^ : FQI90N08 ^ 80V/71A ^5(〇N)=12mQ ^ I2PAK &&& ·· IRFP264N, 250V/44A, (4)=60mQ, TO-247

Lx : 7/iH L2 : 60//H Q : 22//F/100V C2 : 10//F/200V

ZV and D3x: STPS20H100CT, 100V/2* 10A (Schottky), TO-220AB /3⁄4 : SF1005G, 300V/16A, TO-220A In order to further understand the contents of the present invention, the experimental waveforms of the following embodiments, circuit components For the voltage and current codes, please refer to Figure 3(a). The high-efficiency high-voltage ratio bidirectional converter step-down part of the circuit is implemented as shown in Figure 9. When the high-voltage circuit voltage is 4=200V and the low-voltage circuit voltage匕=24¥, the experimental waveform of each component when the output power is 300W. Figure 9(a) shows the voltage-current waveform '' of the low-voltage switch during synchronous rectification control's switching voltage VMr50V, which is in line with theoretical analysis. Figure 9(b) and Figure 9(c) show the voltage and current waveforms of the buck switch & and the high-voltage switch & respectively, as shown in the figure, when the two switches are turned on with zero voltage switching characteristics, and when turned off, the voltage powder is restricted. At 200V. Figure 9(d) shows the waveform of the variation of the winding k and the heart current on both sides of the coupled inductor. Fig. 10 is a view showing an embodiment of a high-efficiency high-voltage differential ratio bidirectional converter circuit of the present invention. When the high-voltage circuit voltage is ^=200 and the low-voltage circuit voltage is Kz^24V, and the output power is 300W, the experimental waveform of each component. Fig. 1〇(8) 30 1262646. For the low-voltage switch & voltage and current waveform, its switching voltage, approximating the theoretical analysis of equation (22), the current has a zero-current switching characteristic and is close to a low-chopper square wave. Figure 10(b) shows the voltage and current waveforms of the high-voltage switch & during synchronous rectification control, with voltage clamping less than 200V. Figure 10(c) shows the waveform of the current changes in the windings k and 4 on both sides of the coupled inductor. The measured efficiency of the high-efficiency high-voltage difference ratio bidirectional converter step-up and step-down circuit of the present invention is shown in Fig. 11. The highest step-down conversion efficiency is about 95.5%, and the maximum boosting conversion efficiency is over 96%. The light load efficiency boost 10 is higher than the buck system because the zero voltage switching of the buck circuit has a higher circulating current, while the boosting efficiency of the heavy load region is poor. Most of the energy transfer is caused by the operation of the low voltage switch, and the conduction loss is rapidly increased. Figure 12 is a block diagram of a second preferred embodiment of the high efficiency high voltage differential ratio bidirectional converter of the present invention. The architecture is similar to the first preferred embodiment described above, and the operating principle is similar, but the clamping circuit 123 reduces the clamping inductance A and the third clamping diode D3; c than the components of the clamping circuit 103. According to the specification of the first preferred embodiment, in the same power output condition, the result of the simulation is as follows: the step-down circuit analog waveform response of the second preferred embodiment shown in FIG. 13, and the second preferred embodiment of FIG. The boost circuit simulates the waveform response. Referring to Fig. 13 and Fig. 9, the cut-off voltage of the high voltage switch & of Fig. 13(c) is 匕-να, which is smaller than the same switch of Fig. 9(c), and the switch of the lower rated voltage can be further selected. However, the voltage of the step-down switch of Fig. 13(b) is increased to vα, and only a near-zero voltage flexible switching can be achieved, so that the two preferred embodiments have their respective advantages in terms of down-and-down. Comparing Fig. 14 and Fig. 10, the boosting part performance, the low voltage switch & and the high voltage opening 1262646 of Fig. 14(a) and Fig. 14(b) are better than the Fig. 10(a) and Fig. 10(b), this is the third clamped diode and the clamped inductor A in the second preferred embodiment, so that the capacitor voltage % can be released faster and can support a part of the voltage when the high voltage is turned on. The present invention has been disclosed in the preferred embodiments as described above, but it is not intended to limit the scope of the invention, and any person skilled in the art can make various kinds without departing from the scope of the present invention. The invention is subject to change and modification, and therefore the protection of the present invention is defined by the scope of the patent application. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a circuit diagram of a high-efficiency high-voltage differential ratio bidirectional converter of the first preferred embodiment of the present invention. ^ Figure 2 shows the efficiency of the high voltage difference ratio of the bidirectional converter of the invention. Figure 4 is a diagram showing the step-down operation mode of the high efficiency high voltage difference ratio bidirectional converter of the present invention. The high-efficiency high-voltage difference of the present invention is based on the relationship between the step-down ratio of the step-down ratio Gn and the duty cycle 4 of the step-down portion of the bidirectional converter. The efficiency difference of the present invention is higher than that of the boosting portion of the bidirectional converter. Fig. 6 shows the boosting mode of the efficiency of the high voltage difference ratio bidirectional converter of the present invention. Electric tower Figure 7 The present invention is also a high-voltage difference ratio bi-directional converter boosting part of the circuit, in different о-numbers, the boost ratio ~ and low-voltage ^ off 1262646 & duty cycle 4 relationship, and with the use The voltage gain of the coupled inductor circuit is compared. Figure 8 is a high-efficiency high-voltage differential ratio bidirectional converter step-down circuit of the present invention, designed high-voltage circuit voltage 4 2 200V, at different turns ratio I, low-voltage switching voltage, low-voltage circuit voltage ^ and high-voltage switch & duty cycle 4 relationship curve. Fig. 9 shows an embodiment of the high-efficiency high-voltage difference ratio bidirectional converter step-down circuit of the present invention. When the high-voltage circuit voltage is ^=200¥, the low-voltage circuit voltage ί^=24ν, and the output power is 300W, the components are experimentally shaped. Fig. 10 shows an embodiment of the high-efficiency high-voltage difference ratio bidirectional converter boosting section circuit of the present invention. When the high-voltage circuit voltage is 4 = 20 〇 ν, the low-voltage circuit voltage is ^ = 24 ν, and the output power is 300 W, the components are experimentally shaped. Figure 11 shows the measured conversion efficiency of the high efficiency high voltage difference ratio bidirectional converter step-up and step-down circuit of the present invention. Figure 12 is a circuit diagram showing a high efficiency high voltage difference ratio bidirectional converter of the present invention, a second preferred embodiment. Figure 13 is a high efficiency high voltage difference ratio bidirectional converter of the present invention, and the buck circuit of the second preferred embodiment simulates a waveform response. Figure 14 is a high efficiency high voltage difference ratio bidirectional converter of the present invention, and the booster circuit of the second preferred embodiment simulates a waveform response. [Main component symbol description] 101: Low voltage circuit 1262646 102: Medium voltage circuit 103: Clamp circuit 104: High voltage circuit 105: Step-down circuit 123: Clamp circuit ^: High voltage circuit voltage 匕: Low voltage circuit voltage A: Low voltage work _ rate Semiconductor switch (referred to as low voltage switch) & : Buck power semiconductor switch (referred to as buck switch) 5^: South voltage power semiconductor switch (referred to as South voltage switch) 7;: transformer with high excitation current (referred to as coupled inductor) : Coupling inductor 7; coupling coefficient: coupled inductor primary winding As: coupled inductor secondary winding

Lk\ : Leakage inductance of the primary winding of Momma inductor Lja: Leakage inductance of the secondary winding of the coupled inductor Lml : Magnetizing inductance of the primary winding of the coupled inductor ^m2 : Magnetizing inductance of the secondary winding of the coupled inductor A Clamping inductor l2 Buck inductor Q clamp capacitor c2 medium voltage capacitor A first clamp diode d2 step-down diode 34 1262646 A: second clamp diode: third clamp diode

Claims (1)

1262646 X. Patent application scope: 1. A high-efficiency high-voltage differential ratio bidirectional converter, in which the 々8-low-voltage circuit: consists of a low-voltage switch and a coupled inductor = with a low-frequency switch-on and turn-off group primary side The energy of the winding; the light-inductance of the light-cutting inductor: a medium-voltage circuit: the coupling is reduced by one, the gamma is implanted (10), the one-side winding and the middle-capacitor capacitor are composed of ^ 丨 ( (four) road and "turn between, mainly in use Each of the voltage increases the boost ratio or withstands a part of the voltage during the step-down; - the clamp circuit: consists of a clamped inductor, a clamped capacitor, a first clamped diode, a second clamped diode, and a third clamped Polar body: into 'mainly absorbs the leakage inductance energy of the turn-in inductance, protects the low-dust switch, and releases the absorbed energy to the output end; 1press pen path: consists of a high-voltage switch, which provides the path to achieve high voltage Bidirectional energy transfer between circuit and low voltage circuit; - Buck circuit: consists of a step-down switch, a step-down inductor and a step-down diode, which is responsible for discharging the discharge circuit of the medium voltage capacitor; Kind of work Boost aspect: Define the low-voltage circuit as the power supply 'the high-voltage circuit is the load; when the low-voltage switch is turned on, the primary winding of the coupled inductor is in the charging state, and the medium-side capacitor is charged through the coupled inductor primary-side winding' combined with the clamped capacitor; When the switch is turned off, the leakage inductance energy of the horse-inductor is absorbed by the clamp capacitor; when the leakage inductance is greatly reduced, the windings on both sides of the coupled inductor combine the low-voltage power supply voltage and the medium-voltage capacitor to provide the high-voltage circuit 1262646 power through the high-voltage switch; Pressure: Define the high voltage circuit as the power supply, the low voltage circuit as the load; when the high voltage switch is turned on, the high voltage circuit charges the medium voltage circuit and the low voltage circuit; when the high voltage switch is turned off, the coupled inductor energy is all looped through the synchronous rectification state. The side winding is transmitted to the load of the low voltage circuit. At this time, the medium voltage capacitor is also provided by the low voltage switch and the step-down switch, and is supplied to the load of the low voltage circuit through the secondary winding of the coupled inductor and the buck inductor; Use two switches to complete the bidirectional current control, plus this architecture has The characteristics of the rising and lowering ratios can be used to integrate the high-voltage busbars with low-voltage batteries to facilitate the use of high-voltage loads or reverse-flow terminals. The switching technology of the inverters uses voltage clamping and V 1 The voltage zero current mode is used to fully utilize the component specifications, so the device has the advantages of high buck-boost ratio, low switching loss and low conduction loss. ' 2· ^ Patent Application Scope Item 高 High Efficiency High Pressure Difference Ratio Bidirectional Change ^ ^ 'The low-voltage circuit and the medium-voltage circuit are combined with the inductor, which is a high-excitation current double-winding transformer with a return air gap; the transformer turns ratio is different, the voltage and current range are separated, and the number of turns on the low-voltage side is small. The current is large, and the south side is opposite. The high-efficiency high-voltage difference ratio bidirectional converter described in the first paragraph of the patent scope of the patent, wherein the clamp circuit can absorb the leakage energy of the primary winding of the coupled inductor, and the absorbed energy can be It is used for boosting or stepping down. It is a coupling inductor used in this clothing. It can accept high leakage inductance transformers. It is not limited to the use of sandwich winding method with high conversion coefficient. ! 2626464-around paper separately around the law to complete. 1 high efficiency high voltage difference than bidirectional converter, eight 7 voltage circuit: by a low voltage open and close inductance switch by the low barrier switch conduction and cutoff, will store or release the energy of the transduction ~ secondary winding; electricity: medium voltage Circuit: The secondary side winding and the medium voltage capacitor group of the inductor are connected between the low voltage circuit and the high voltage circuit, and the main money utilizes the medium voltage capacitor to increase the boost ratio or to withstand some voltage during the step-down; Clamping circuit: consisting of - clamping capacitor, - first clamping diode and one: two clamping diode, mainly to absorb the leakage inductance of the light coupling inductance, protect the low voltage switch, and release the absorbed energy at the output end , · A pressure circuit · consists of a high voltage switch, using the switch to provide a roller to achieve two-way energy transfer between the high voltage circuit and the low voltage circuit; buck circuit: a buck switch, a buck inductor and a buck diode The body composition is responsible for releasing the discharge circuit of the medium voltage capacitor; the ι has a total of two functions of boosting and stepping; the boosting aspect: defining the low voltage circuit as the power source, the high voltage circuit as the load; when the low voltage switch is conducting, the coupling inductor is on the primary side Winding is In the state of charge, the secondary winding of the coupled inductor is combined with the clamp capacitor to charge the medium voltage capacitor; when the low voltage switch is turned off, the leakage inductance energy of the light coupling inductor is absorbed by the clamp capacitor; when the leakage inductance is greatly reduced, the coupled inductor The two sides of the winding combined with the low-voltage power supply voltage and the medium-voltage capacitor provide the high-voltage circuit power through the high-voltage switch. "Buck-proof aspect: the high-voltage circuit is defined as the power supply, the low-voltage circuit is 38 1262646 - the load; when the high-voltage switch is turned on, the high-voltage circuit is connected to the medium-voltage The circuit and the low-voltage circuit are charged. When the south-voltage switch is turned off, the coupled inductor energy is all passed through the loop of 5 V t, and the primary winding is transmitted to the low-voltage circuit: load 'At this time, the medium-voltage capacitor is also controlled by the low-voltage switch. The buck switch raises the loop and supplies power to the load of the low-voltage circuit through the secondary winding of the coupled inductor and the buck inductor; /, specifically, the control of the bidirectional current is completed by using only three switches, and the structure is modified. The characteristics of the rising and lowering ratios, so the low-pressure storage can be used to integrate the high-pressure busbars to facilitate the post-stage high-voltage load or reverse flow. The end uses; the converter switching technology uses voltage clamping, synchronous rectification and zero voltage zero current mode to fully use the component specifications, so the clothing has the effect of lowering the voltage drop ratio 'low switching loss and low conduction loss. 5 ·=Please refer to the patent range 帛4帛 for the high a-rate high-voltage difference than the bi-directional change, where the coupling inductance of the low-voltage circuit and the medium-voltage circuit is a localized excitation current double-winding transformer with a return air gap; The transformer turns ratio is different from the 'divided voltage and current range, the low voltage side turns less current and the high voltage side is the opposite. 6 · t patent application scope item 4 of the high efficiency high pressure difference ratio bidirectional commutation In addition to absorbing the leakage inductance energy of the primary winding of the coupled inductor, the absorbed energy can be used for boosting or stepping down. Therefore, the coupled inductor used in the device can accept a high leakage inductance transformer, and is not limited to using a high coupling coefficient. The sandwich winding method can be completed by using a conventional two-winding winding method.