TWI239136B - High-efficiency high-boost-ratio dc/dc converter with reduced peak switch voltage stress - Google Patents

Abstract

The aim of this invention is to develop a high-efficiency high-boost-ratio DC/DC converter with reduced peak switch voltage stress. In general, a high-boost-ratio DC/DC converter is employed for many applications via the power source of low-voltage batteries. For examples, a high intensity discharge (HID) lamp, the high-voltage dc bus of an uninterruptible power supply (UPS), a travelling wave tube amplifier (TWTA), etc. In order to satisfy the requirement of high-voltage demand, a high-efficiency high-boost-ratio converter is one of the essential mechanisms in power supply systems with low-voltage sources. The high-efficiency high-boost-ratio DC/DC converter with reduced peak switch voltage stress utilizes a three-winding coupled transformer for providing a high conversion ratio without the extreme switch duty-cycle. This three-winding coupled inductor is also facilitated to reduce peak switch voltage stress for decreasing the conduction loss, and to reduce the turn-off rate of the output diode for alleviating the reverse-recovery problem. It can achieve the property of high-efficiency power conversion. The high-efficiency high-boost-ratio DC/DC converter with reduced peak switch voltage stress can be used for low-voltage sources, such as conventional batteries, fuel cells, photovoltaic and wind energy, to further increase the energy utility rate.

Description

1239136 D. Description of the invention: [Technical field to which the invention belongs] Applications for multiple power sources, such as gas discharge headlamps, high-voltage DC busbars of inverters in uninterruptible power systems, wideband traveling wave tube amplifiers, etc., both A high-voltage DC power supply is required. However, traditional batteries are generally used as the power source. Therefore, the development of a high boost ratio converter is a necessary power conversion mechanism. The high efficiency and high boost ratio converter with reduced switching withstand voltage performance of the present invention can convert the low output voltages of traditional storage batteries, fuel cells, solar power and wind power to high voltage DC power supply systems, which greatly improves energy utilization. Rate and increase power supply stability. The technical field covered by the present invention includes the fields of power electronics, DC / DC converter technology and energy technology.``Although the technical field involved in the present invention is wide, it is mainly to develop high efficiency and high boost voltage with reduced switching withstand voltage performance. Than the inverter device to improve the lack of conventional inverters. [Previous technology] Traditional boost converters can adjust the duty cycle of the output voltage by adjusting the duty cycle of the switch. When applied to high boost ratios, the duty cycle needs to be adjusted to a maximum value. However, the equivalent resistance (ESR) of the inductor in the converter causes the boost ratio to be limited. It cannot operate in a situation where the boost ratio exceeds 7 times and the conversion efficiency is not good. Furthermore, when the power semiconductor switch of the boost converter is turned off, the voltage value at both ends is the output voltage, which is a voltage that is several times higher than the input voltage, forcing the power semiconductor to choose the high withstand voltage. And it has a larger two = (Rds ^ w) 'forming a higher conduction loss. In addition, the diode in the traditional boost converter 1239136 has a reverse-recovery problem. During the transient state of the power semiconductor switch, the diode must use an instantaneous high current to establish the reverse bias. Voltage, this current flows through the power semiconductor switch, causing severe switching losses and low conversion efficiency. Based on the above, the traditional boost converter does not have a high boost ratio function, so it is limited to DC power conversion applications with a boost of 7 times or less, and cannot achieve a high-efficiency power conversion mechanism. Therefore, many experts have learned to propose a boost converter technology to improve the shortcomings of the conventional boost converter. The following is a comparison of the world's leading boost converter technologies to further highlight the advantages of the invention's breakthrough in high efficiency and high boost ratio converter technology with reduced switching withstand voltage performance. 1. CW Roh, SH Han? MJ Youn, uDual coupled inductor fed isolated boost converter for low input voltage applications, "Electronics Letters, \ o \. 35, pp. 1791-1792, 1999. 2. E · S. Da Silva L. dos Reis Barbosa, JB Vieira, Jr., LC de Freitas, and VJ Farias, "An improved boost PWM soft-single-switched converter with low voltage and current stresses / 9 IEEE on on Industrial Electronics ^ vol. 48? pp. 1174-1179, 2001. 3 · Q. Zhao, and F · C · Lee, “High-efficiency, high step_up DC-DC converters ^ IEEE Transactions on Power Electronics ^ vol. 189 pp. 65-73,2003. 4 · DC Lu, DKW Cheng, and Y · S. Lee, "A single-switch continuous-conduction-mode boost converter with reduced 1239136 reverse-recovery and switching losses / 9 IEEE Transactions on Industrial Electronics ,, vol. 50, pp 767-776, 2003. 5. K. Hirachi, and M. Nakaoka, "UPS circuit configuration incorporating buck-boost chopper circuit with two magnetically coupled coils / 5 Electronics Letters, vol. 39? Pp. 1345-1346, 2003. 6 · C · M · C · Duarte, and I · Barbi, "An improved family of ZVS_PWM active-clamping DC-to-DC converters ^ IEEE on

Power Electronics ^ vol. 17, pp. 1-7, 2002. References Input Voltage Output Voltage Output Capacity Conversion Efficiency Circuit Architecture Comparison of Advantages and Disadvantages [1] 12V 150V 90W 87% Dual Coupling Inductor Advantages: High Boost Ratio Disadvantages: Complex Architecture [2] 80V 200V 400W 97.5% Transformer Advantages: Flexible switching Disadvantages: Up to four times the boost ratio [3] 60V 380V lkW 91.8% Handle-clamping Advantages: Simple structure and use of lower conduction loss parts (250V switch) Disadvantages: The step-up ratio cannot be greatly improved, the efficiency is not good when the voltage is low, and it is unable to overcome the line electrical surge [4] 100V 150V 200W 95% coupled spectral vibration advantages and flexible switching disadvantages: low step-up ratio and inductance ___ wheat amount Large— Advantages: Single-stage DC boost to AC Disadvantages: Ca n’t be used for voltage change ——— Battery battery [5] 48V 340V 700W 86% Uninterruptible power system 1239136 and switch withstand voltage Qin [6] 300V 400V 1.6kW 98% Active clamping ——_______ Ι " ΓΊ ^ '_ΤΓΤ_ 1 Advantages: Flexible switching Disadvantages: Low boost ratio and high clamping voltage The high efficiency and high efficiency of the switch with reduced voltage withstanding capability disclosed by the present invention Compared with the converter, the three-winding coupling inductor is used to make the iron powder core operate more efficiently in the whole region. Without increasing the duty cycle of the power semiconductor switch, the boost ratio of the traditional boost converter can be greatly improved. It also helps to reduce the withstand voltage specifications of the switch and reduce the conduction loss. On the other hand, because the coupling inductor has the characteristic of leakage inductance, it reduces the surge current of the reverse recovery of the diode at the output terminal, and achieves high-efficiency low-voltage DC power conversion Purpose of high voltage DC power supply. [Summary of the Invention] Figure 1 shows the high efficiency of the switch withstand voltage reduction efficiency disclosed in the present invention: a block diagram of a boost ratio converter, which includes a DC input circuit 101: DC input, voltage [and input filter ' It is composed of wave capacitor q; the DC input voltage dagger is connected in parallel with the 电容 wave capacitor, which can reduce the DC input voltage "ripple; a primary circuit 102: a light-on inductor primary side A and a power semiconductor switch Clever construction, light closing inductor-secondary side & series connection with power semiconductor switch f 'ff power semiconductor on f on / off control _ switching inductance-secondary side 2 丨 storage and release inside, primary and secondary circuit 1〇 3: 2 coupled inductors, 12 poles-composed of pole body A and a capacitor C2; two light-sense inductors ^ 2 "-pole body D2 connected in series, and then connected to the parallel capacitor C2;-three times' J The circuit 104 is composed of the third side of the inductor—a diode ^ and a 1239136 capacitor c3; the third side of the coupling inductor z3 is connected in series with the diode / ¾, and then the same parallel capacitor c3 is used; 105: one diode A, output filter capacitor Q, and load Diode / ¾ connected to filter capacitor C; the positive terminal, and at the same time, filter capacitor C0 is also connected in parallel with the load; a closed loop control mechanism 106: the error value is generated by comparing the voltage command with the feedback of the DC output voltage G, After proportional integral control, pulse width modulation and driving amplifier circuit, the output is a driving signal vg with adjustable duty cycle ratio, and the power semiconductor switch S is triggered and cut off. The combination of the primary side circuit 102, the secondary side circuit 103, and the tertiary side circuit 104 is to connect the positive end of the primary side 4 of the coupled inductor to the negative side of the tertiary side A of the coupled inductor, and the negative side of the primary side of the coupled inductor and power. The drain terminal of the semiconductor switch S is connected to the negative terminal of the tertiary-side circuit 104 capacitor C3, and the output terminal of the tertiary-side circuit 104 diode / ¾ and the tertiary-side circuit 104 are connected to the positive terminal of the capacitor C3 for a second time. The positive terminal of the side L2 is connected to the negative terminal of the capacitor C2 of the secondary-side circuit 103. The present invention utilizes a DC input power supply, and after the disclosed high-efficiency and high-boost-ratio converter power supply with reduced switching withstand voltage performance, the level of the DC input voltage R is greatly improved, which can be applied to occasions where high voltage is required ; When the power semi-conductor switch S of the primary circuit 102 is turned on, first store the energy of the DC input voltage source on the primary side of the coupling inductor of the primary circuit 102, and store the energy of the DC input voltage source three times through the coupling inductor The capacitor C3 of the side circuit 104; when the power semiconductor switch S of the primary circuit 102 is turned off, the DC input voltage source, the coupled inductor primary side, the capacitor C2 of the secondary circuit 103 and the capacitor C3 of the tertiary circuit 104 The series energy is conducted to the DC output circuit 105 in a current mode when the diode of the DC output circuit 105 is turned on, and the DC output voltage of 12 I239136 is raised; at this time, the capacitor Q and the voltage of the secondary side are 3: circuit 104 The capacitor C3 withstands the difference between the output voltage of most DC output circuits and the voltage across this voltage. In the turn, the voltage is much smaller than the direct cause. Therefore, the power semiconductor switch of the secondary circuit 1G2 has a low withstand voltage. The coupling inductor-secondary current starts to decrease and gradually becomes zero. Continuous characteristic, showing the secondary side current of the coupled inductor C = increases, and when approaching the ridge value, the capacitance of the secondary side circuit starts

Li therefore, the voltage of the capacitor ^ reaches equilibrium in a period. The principles and comparative effects of the prior art collected today are as follows: • = of the side circuit 102, the secondary side circuit 103 and the tertiary side circuit 104

Combined, it has the effect of increasing the boost ratio and reducing the financial pressure of the power semiconductor switch $: By utilizing the characteristic that the number of turns of the coupled inductor is proportional to the voltage, the device of the present invention has the characteristics of high boost ratio and provides higher than traditional Boost ^ converter boost ratio; the capacitor Q on the secondary side circuit 103 and the voltage on the capacitor q on the three-side circuit 104 share the power of the primary side circuit Cross voltage, make this voltage lower than the output voltage & of the DC output circuit 105. 2 · Reduce the power semiconductor switch $ financial voltage specification to reduce the conduction loss: the cross-voltage across the power semiconductor switch $ of the primary circuit 102 is limited to the low voltage range. MOSFETs with lower withstand voltage can be selected because they have lower ^ Impedance can reduce conduction loss and improve conversion efficiency. When: Core utilization rate: When the three-winding coupling inductor is used, the current on the tertiary side of the coupling inductor is charged to the capacitor ^ of the third-side circuit 104 when it is turned on, which is similar to the working principle of the traditional forward commutation cry. When the power semiconductor switch S is turned off, the energy stored in the inductor passes through the secondary side of the coupled inductor, releases energy to the load end, and then charges the capacitor C2 of the secondary side circuit 103. This working principle is similar to that of a traditional flyback converter Based on the above, under the full-range operation of the three-winding light-coupling inductor, the utilization ratio of the coupled inductor iron powder core is increased. 4. The leakage inductance of the coupled inductor reduces the problem of reverse recovery of the diode at the output terminal: When the power semiconductor switch of the primary circuit 102 is turned off, the diode at the wheel output terminal is turned on-the slope of the pole current is the leakage inductance function of the coupled inductor. Its current is reduced to zero and cut off, which reduces the problem of reverse recovery, which does not cause reverse current surges, reduces component heating and power noise, and thereby improves conversion efficiency. 5. Closed edge, control mechanism 106: DC input of general DC input circuit 2: The voltage K is easy to change with the load, and the DC output voltage of the DC output circuit 105 can be rushed by the closed-loop control mechanism 106. &. [Embodiment] ° FIG. 2 shows the high-efficiency circuit with reduced switching withstand voltage disclosed in the present invention = an equivalent circuit of a step-up ratio converter, in which the three-winding light-winding inductor uses an ideal transformer and excitation of Inductance & equivalent leakage inductance ^ indicates that, the E number of this ideal transformer is%,%, and%, and its ratios ~ and% can be expressed as follows: (1) (2) the capacitance C2 and the three 'assumed two The secondary side circuit η2, Ν2 丨 Νγ η3 defines the primary side-span voltage to be Ϊ239136-the capacitance q of the human-side circuit 1G4 is large enough to be regarded as a constant voltage source, and its voltage is dagger 2 and dagger 3 ′ and the DC input circuit 1 〇 1 Simplified to a constant voltage source g. FIG. 3 shows the voltage and current waveform timings of the converter disclosed in the present invention. FIG. 4 shows the working mode of the present invention, which is explained as follows: Mode 1 [~ G]:

… When the time household 6 is turned on, the power semiconductor switch S is turned on, the diodes are reverse biased from A, and the first pole £ & 3 is turned on. At this time, the DC input voltage charges the capacitor q of the tertiary-side circuit 104 through the coupling inductor, Kirchhoff's law of voltage and current can be used to derive the rate of change of the capacitor charging current ^, the magnetizing inductor current ^, and the light-inductance primary-side current 仏 as follows: ^ 1 ==-m 仏 ":, dt n3 \ (3 )

UC3-VS dt n, Lm (4) djjA ^ (^ + n3) Vs-VC3 dt — '(5) and the voltage on the magnetizing inductor

(6) n3 mode-Medium ’DC input μ is used to charge the magnetizing inductor 4 and the leakage inductance.” The capacitor c3 of the secondary circuit 104 is charged, and the energy is stored in the leakage inductance 4 of the magnetizing inductor 1 and the capacitor c3. Mode 1-[~ < 2 I: When the voltage across the switch is' diode ^ inverse time, the power semiconductor switch S is turned off, 4 rises to G-FC2-factory C3, and diodes A and Z) 2 are turned on 15 1239136 The bias, magnetizing and coupling inductance leakage currents flow through the capacitor q of the secondary-side circuit 103 and the capacitor 104 of the tertiary-side circuit ^ to release energy to the load; ideally, the transformer uses magnetic coupling to The energy on the excitation inductor is conducted to the ideal transformer secondary side%, and the current on the secondary side% of the transformer also flows to the DC output circuit 105 to release energy to the load. Using Kirchhoff's voltage law, the relationship of voltage can be derived as follows:

Vds (() + VC2 + VC3 = V〇⑺ VC2 = ^ 2 ^ Nl (t) ⑻ vL ^ (0 = vNl (t)-^ (V ^ hVu (0 ^ KX (9) l + «2 at this time The withstand voltage on the switch is

Vds (0 = vs- VNI (t) ~ VLk (t) = V〇-VC2-K: 3 (10)

< K It can be known from formula (10) that the efficiency of the switching device in reducing the withstand voltage of the switch helps to select a semiconductor switching element with a low withstand voltage and a low conduction loss, so as to improve the conversion efficiency of the converter. Using the above voltages of the excitation inductance 4 and the coupling inductance leakage inductance 4, the current change rate can be derived as follows: ^ L: (^ C2 \ (11) dt — (r) n2Lm dt: n2 (-V0 + Vs + VC3) + (l + n2) VC2 n2 (12) dt = n2 (V0 ~ Vs-VC3)-(Un2 + Lk / Lm) VC7 n22 Lk (13) (14) 1239136 Yu = u2 (-k + r + d + ( i + ^ fC2 at 1 2 τ «2 4 mode n22Lm [G ~ 6]: When the time is 6, the discharge current of the capacitor C2 of the secondary circuit 103 decreases to zero '. The energy of the magnetizing inductance passes through the ideal transformer. The capacitor c2 of the secondary circuit ι03 is charged, so the current of the capacitor c2 shows a negative value, and the current change rate is represented by equation (14). On the other hand, the capacitor Π of the tertiary circuit 104 continuously discharges the load, which The current change rate can be expressed by the formula (12), and the current of the series path decreases with time. Mode 4 [6 ~ 纟 4]: When the time is 6, the current of the primary side of the coupled inductor decreases to zero, ZZ · Z1 (纟 3)-0 The stored energy of the consuming inductor is represented by the secondary side current of the face-to-face inductor. At this time, the diode A is reverse biased and the current 'decreases to zero. The current cut-off rate is as shown in equation (12). All It can alleviate the problem of the current surge caused by the output diode D. Reverse recovery, and the energy stored on the field inductor continues to charge the capacitor Q of the secondary circuit 103, and the current change rate on the field inductor As shown by formula (11), the current of the magnetizing inductor decreases linearly, and the change rate of the charging current of the capacitor C2 of the secondary circuit 103 is ^ diD2 = VC2 dt dt-n22 Lm (15) The two poles of the primary circuit 103 The body current core 2 is proportional to the current k of the magnetizing inductor, and the diode current k is a linear decreasing function. Because the leakage current is zero and the current change rate is zero, the voltage on the leakage inductance is zero. , 1239136 reduces the voltage of the power semiconductor switch s, and the voltage value across the power semiconductor switch can be expressed as (16)

Vds (0 = K ^ VNl (0 Assuming all components are ideal, the capacitor voltage K2 of the secondary side circuit 103 and the capacitor voltage K of the tertiary side circuit 104 can be expressed as KC2 =-<2 ('), Tx &lt; t &lt; tA (17) VC3 = (l + n3) Vs (18)

Let the duty cycle for turning on the power semiconductor switch S be d, and use formula (6), formula (9), formula (17), formula (18) and the average voltage of the magnetizing inductor in a cycle to be zero, which can be deduced The compression ratio is as follows:

KI — dd f- ld (19) It can be known from equation (19) that the boost ratio of this circuit is higher than that of the traditional boost converter, and the traditional boost converter can be compensated by adjusting the turns ratio. Insufficient compression ratio. FIG. 5 shows one of the embodiments of the high-efficiency and high-boost converter with reduced switching withstand voltage efficiency disclosed by the present invention. The low-voltage power source used is a fuel cell PowerPEMTM_PS25 produced by the American company H_Power. The rated output of this fuel cell The power is 250 watts and the rated output voltage is 28 volts. In this embodiment, in accordance with the voltage and current specifications of the fuel cell output and the 400 volt DC voltage output by the DC output circuit 105, a high-efficiency and high-boost converter element disclosed in the present invention with reduced switching withstand voltage performance is appropriately selected. The power semiconductor switch S is selected IRFPS4710 (100V, 1 ^ (〇 &gt; 0 to 14mQ), has a low on-resistance, which is beneficial to reduce the on-conduction loss, and greatly improves the conversion efficiency of the converter 1239136. Diode A uses a Schottky diode SR20100 It can also reduce its on-state voltage to improve efficiency. The diode / ¾ and A are selected as SFA1608. The parallel damping circuit RCD is at the ends of the diodes 2 and 3 to reduce the reverse bias of the diode. Due to the voltage surge caused by the parasitic capacitance of the diode and the leakage inductance resonance of the secondary and tertiary sides of the coupling inductor, the closed-loop control mechanism 106 uses a TL494 pulse width modulation control chip, and the frequency of the power semiconductor switching element is operated at 100 kHz. The output power is 20 ~ 300 watts. The detailed specifications of this embodiment are as follows:

Vi: 27 ~ 38V V. : 400V K: 534 ~ 8000Ω c2: 4.75 // F C3: 4.75 β F Q: 2200 // F C〇: 100 // F A: 10.7 // H Lk: 0.6 // H n2: 6.33 n3: 5

One of the embodiments of the high-efficiency and high-boost-ratio converter with reduced switching withstand voltage efficiency disclosed by the present invention operates at an output power of 300 watts, the measured efficiency is 94.1%, and the measured waveform response is recorded as follows. Figure 6 shows the measured voltage and current waveforms of the power semiconductor switch S. The figure shows that the parasitic capacitance is charged when the power semiconductor switch is turned off, and the voltage at both ends rises. 19 1239136 Due to the effect of line leakage inductance, the switching voltage has the phenomenon of oscillation and stability. This voltage is about 60 volts. Figure 7 shows the measured waveforms of the coupled inductor primary current / Z1, the coupled inductor secondary current zD2, and the coupled inductor tertiary current. The figure shows the response of the coupled inductor primary and secondary currents during the energy transfer in the coupled inductor. And the charging current of the coupling inductor C3 to the capacitor C3. Figures 8 (a), (b) and 表示 show the voltage and current waveforms of diodes, Z) 2 and Z) 3, respectively. Figure 8 (a) shows that diode A has almost no reverse direction when it is turned off. The current surge effectively reduces the problem of reverse recovery. Figure 9 shows the response of the DC output voltage, DC output current tolerance, and DC input current of the fuel cell when the load changes between 0 watts of no-load output power and 300 watts of full-load output power, in cooperation with the closed-loop control mechanism 106 Under high-frequency operation, the ripple of the DC input current of the fuel cell and the output voltage of the DC output circuit 105 is small, which enables the fuel cell to work stably and output a DC voltage of 400 volts. FIG. 10 shows one of the embodiments of the high-efficiency and high-boost-ratio converter with reduced switching withstand voltage efficiency disclosed by the present invention, which uses a fuel cell as a DC input voltage and operates at different output powers corresponding to the conversion efficiency, the highest conversion Efficiency is greater than 95%. FIG. 11 shows a block diagram of another preferred embodiment of a high-efficiency and high-boost converter with reduced switching withstand voltage efficiency disclosed in the present invention, which includes a DC input circuit 101: a DC input voltage R and an input filter capacitor 6 The DC input voltage G is connected in parallel with the filter capacitor &lt; ^, which can reduce the DC input voltage K ripple;-the secondary circuit 102: a coupling inductor primary side A and a power semiconductor switch S; coupling The primary side A of the inductor is connected to the body of 1239136, # cut-off control coupling electric 4 a female θ thousand ¥ body switch $ on / thunder ^ storage and release of this side A, the primary side i: c: ^ Then, parallel connection = capacitance? Inductance Γ side W2 is connected in series, series, upper pole :: circuit 104: a sense of three-the pole body is 3 and a capacitor c3] circuit: a capacitor c, an inductor 々 and a two-pole ❹α have been constructed as follows: In the formula, capacitor 4 is used, and the two-pole material is connected in series with inductor 4; the load Γ is covered by the circuit 105: a diode D °, the output 遽 wave capacitor 仏, and The two diodes are used to form a 'diode Z) 0 connected to the chirped wave capacitor c. The positive terminal is simultaneously filtering the electric valley C; it is also connected in parallel with the load &lt;; closed-loop control mechanism 106: an error value is generated by comparing the electric command with the DC output voltage F0 feedback, and the proportional = minute control, pulse The wave width modulation and driving amplifier circuit outputs the driving signal Vg with adjustable duty cycle ratio, which triggers and cuts off the power semiconductor switch X. The combination of the primary circuit 102, the secondary circuit 103, the tertiary circuit 104 and the auxiliary circuit 1104 is to connect the positive terminal of the primary side of the coupled inductor to the negative terminal of the capacitor Q of the auxiliary circuit 1104 and the auxiliary circuit 104 capacitor. The positive terminal of c is connected to the auxiliary circuit 1104 at the output terminal of the diode, the negative terminal of the inductor three side 4, and the negative terminal of the primary side A of the coupled inductor is connected to the auxiliary circuit 11 at the drain terminal of the power semiconductor switch. 〇4 The junction of the input terminal of the diode a and the negative terminal of the auxiliary circuit 1104 inductor ，, the positive terminal of the auxiliary circuit 1104 is connected to the negative terminal of the capacitor q of the tertiary side circuit 104, and the tertiary side circuit 10: The output end of the body A and the positive terminal contact point 21 of the capacitor q of the tertiary circuit 104 are connected to the positive terminal 21 of the coupling inductor secondary side 4 and the negative terminal point of the capacitor 103 of the secondary side circuit 103. The biggest difference between FIG. 1 and FIG. 11 lies in the auxiliary circuit 1104. The capacitance Ca of the auxiliary circuit 1104 further increases the output voltage of the DC output circuit 105, and absorbs the leakage inductance in the line to cause the power semiconductor switch S surge voltage; when the power semiconductor When the switch S is turned off, the low voltage and large current of the primary side of the coupled inductor is charged from the capacitor C through the diode of the auxiliary circuit 1104, and the capacitor absorbs the energy of the leakage inductance in the circuit of the primary circuit 102 to slow down the peak voltage of the power semiconductor switch S Shock situation. On the other hand, since most of the primary side current of the coupled inductor charges the capacitor, it reduces the peak value of the current flowing through the diode of the DC output circuit 105. This current path also passes the inductance A of the auxiliary circuit 1104. The purpose of this inductance is to Reduce the current climbing rate, strengthen the function of reducing the peak value of the diode current of the DC output circuit 105, make the current more even, and reduce the conduction loss. FIG. 12 shows another preferred embodiment of the high efficiency and high boost ratio converter with reduced switching withstand voltage efficiency disclosed by the present invention. The fuel cell is used as a DC input voltage, a DC output voltage of 400V and an output power of 300W. Figure 12 (a) is the voltage and current of diode A of the DC output circuit 105. Compared with the current waveform of Figure 8 (a), Figure 12 (a) shows that the peak value of the current is significantly reduced and averaged. This current The path leads to the high-voltage side of the DC output circuit 105. This preferred embodiment has high-voltage low-current and low-voltage large-current characteristics. The characteristics and capacity of the components are fully used to reduce the output voltage and current ripple; Figure 12 (b) is The voltage and current of the diode of the auxiliary circuit 1104 shows that when the power semiconductor switch S is turned off, most of the coupling inductance flows through the diode A of the auxiliary circuit 1104, and the capacitance of the auxiliary circuit 1104 (^ 22 22 1239136 electricity.- Although the present invention has been disclosed in the foregoing preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make various changes without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention shall be subject to the definition of the scope of the attached patent application. [Brief description of the figure] Figure 1 The square block circle of the high efficiency and high boost ratio converter with reduced switch withstand voltage performance of the present invention Figure 2 Equivalent circuit diagram of high efficiency and high boost ratio converter with reduced switch withstand voltage performance according to the present invention. Figure 3 High efficiency and high boost ratio converter with reduced switch withstand voltage performance according to the present invention, voltage and current Waveform timing. Figure 4 The high efficiency and high boost ratio converter with reduced switching withstand voltage performance of the present invention, circuit working mode diagram. Figure 5 The high efficiency and high boost ratio converter with reduced switch withstand voltage performance of the present invention. One of the embodiments is a circuit diagram using a fuel cell as a power source. ® Figure 6 One of the embodiments of the high efficiency and high boost ratio converter with reduced switching withstand voltage performance of the present invention, the power semiconductor switch S spans the voltage 4 and the current core The measured waveforms. Figure 7 One of the embodiments of the high efficiency and high boost ratio converter with reduced switching withstand voltage performance of the present invention, the coupled inductor primary side current z_zl, the coupled inductor secondary side current and the coupled current Measured waveform of the tertiary side current zD3 0 23 1239136 Figure 8 One of the embodiments of the high efficiency and high boost ratio converter with reduced switching withstand voltage performance of the present invention, the measured waveform of the diode voltage and current: (a) of the DC output circuit Diode cross-voltage and current center; (b) Diode Z of the secondary-side circuit) 2 Cross-voltage vD2 and current zD2; (c) Diode Z- of the tertiary-side circuit) Cross-voltage vD3 and current zD3. Figure 9 One of the embodiments of the high efficiency and high boost ratio converter with reduced switching withstand voltage performance of the present invention, the DC output voltage, DC output current tolerance and DC input current of the fuel cell State measured waveform. Fig. 10 is one of the embodiments of the high efficiency and high boost ratio converter with reduced switching withstand voltage performance of the present invention, which operates at the conversion efficiency corresponding to different output powers. FIG. 11 is a block diagram of another preferred embodiment of the high-efficiency and high-boost-ratio converter with reduced switching withstand voltage performance of the present invention. Figure 12 another embodiment of the present invention has a high efficiency and high boost ratio converter with reduced switching withstand voltage performance, the diode voltage and current measured waveform: 跨 DC output circuit diode A across voltage and current k; (b) Diode Z) α of auxiliary circuit and voltage core and current core. The numbers of the main parts of the figure represent the following meanings: 101: DC input circuit 102:-Secondary side circuit 103: Secondary side circuit 104: Tertiary side circuit 105: DC output circuit 24 1239136 106: Closed-loop control mechanism1104: Auxiliary circuit G: DC input voltage: DC input current q: Filter capacitor of DC input circuit Xi: Power semiconductor switch ·· Semiconductor switch driving signal A: Coupling inductor primary side B: Coupling inductor secondary side 尽 End: Coupling inductor tertiary side C2 : Capacitance of the secondary circuit D2: Diode of the secondary circuit C3: Capacitance of the tertiary circuit Z) 3: Diode of the tertiary circuit A: Diode C of the DC output circuit;: DC output circuit The filter capacitor is sufficient: the load of the DC output circuit ® G: the DC output voltage eight: the DC output current Ca: the capacitor of the auxiliary circuit A: the diode of the auxiliary circuit A: the inductance of the auxiliary circuit 25

Claims (1)

1239136 Patent application scope: 1. A high-efficiency, high-boost converter with reduced switching withstand voltage performance, which includes a DC input circuit: a DC input voltage and an input filter capacitor; the DC input voltage is connected in parallel with the filter capacitor Connected to reduce the ripple of DC input voltage; Primary circuit: a combination of the primary side of the inductor and a power semiconductor switch; the primary side of the coupled inductor is connected in series with the power semiconductor switch, and the power semiconductor switch is turned on / The cutoff controls the energy storage and release of the primary side of the coupled inductor; the primary and secondary circuits: a secondary side of the coupled inductor, a diode, and a capacitor; the secondary side of the coupled inductor is connected in series with the diode, and then偕 Same parallel capacitors; one-to-three-side circuit: a coupled inductor tertiary side, one diode, and one capacitor; the three-side of the coupled inductor is connected in series with the diode, and then the same parallel capacitor; one DC output circuit: one two The polar body, the output filter capacitor and the load are called; the diode is connected to the positive end of the filter capacitor At the same time, the filter capacitor is also connected in parallel with the load. A closed loop control mechanism: the error value is generated by comparing the voltage command with the DC output voltage feedback. After proportional integral control, pulse width modulation and driving the amplifier circuit, the output is adjustable responsibility. The driving signal of the cycle ratio triggers and stops the power semiconductor switch. When the power semiconductor switch of the primary circuit is turned on, the energy of the DC input 26 1239136 voltage is stored in the primary side of the coupled inductor of the primary circuit. Store and transfer the energy of the DC input voltage source to the capacitor of the tertiary circuit through the principle of the transformer through the coupling inductor; when the power semiconductor switch of the primary circuit is turned off, the DC input voltage, the coupling inductor primary and secondary circuits The energy of the four capacitors in series with the capacitor of the tertiary circuit is conducted to the DC output circuit in a current mode when the diode of the DC output circuit is turned on, and the DC output voltage of the converter is increased. Capacitors and capacitors of the tertiary circuit withstand most DC output The voltage across the circuit, the difference between the DC output voltage and this voltage is the voltage across the power semiconductor switch of the primary circuit. This voltage is much smaller than the DC output voltage, so the power semiconductor switch of the primary circuit has a low withstand voltage. In the process that the primary side current of the coupled inductor starts to decline and gradually becomes zero, due to the continuous characteristics of the iron powder core, the secondary side current of the coupled inductor rises from zero crossing, and when it approaches the peak, it starts to the secondary side circuit. Capacitance charging; It is characterized by a high step-up ratio, and fully utilizes the voltage value established by the secondary side of the coupled inductor and the tertiary side of the coupled inductor to greatly improve the DC output voltage level; using the three-winding coupled inductor to increase the Frequency magnetic component iron powder core utilization rate; with reduced switching withstand voltage performance, can reduce the power semiconductor switch withstand voltage specifications of the primary circuit, you can choose a lower on-resistance MOSFET to reduce the conduction loss; filtering can be omitted at the output Inductance; the Schottky diode used in the DC output circuit is low voltage and low on-voltage, which can reduce the conduction Loss; low voltage side circuit having a large current, high-voltage low-side current characteristic of the element can be sufficiently used Specifications 1,239,136 and capacity, and therefore more efficient than conventional circuit. 2. The high efficiency and high boost ratio converter with reduced switching withstand voltage performance as described in item 1 of the scope of the patent application, where the capacitor of the DC input circuit is made of general electrolytic capacitor or super capacitor, which can absorb high frequency resonance The component of wave energy stabilizes the DC input voltage. 3. The high-efficiency and high-boost converter with reduced switching withstand voltage performance as described in item 1 of the scope of patent application, where the capacitance of the DC output circuit is mainly to absorb the high-frequency caused by the instantaneous charging current from the secondary circuit. The component of harmonic energy and stabilize the output voltage of the DC output circuit. 4. The high-efficiency and high-boost ratio converter with reduced switching withstand voltage performance as described in item 1 of the scope of patent application, in which the principle of coupled inductor energy transfer of the primary circuit, secondary circuit, and tertiary circuit is the principle The primary coil of the coupled inductor is divided into three stages to boost the voltage. In the first stage, when the power semiconductor switch is turned on, the coupled inductor of the primary circuit is charged on the primary side, and the diode of the tertiary circuit is forward biased through the principle of transformer operation. In the second stage, when the power semiconductor switch is turned off, the diode of the secondary circuit is forward-biased, and the energy stored in the primary side of the coupled inductor is stored in the current mode in accordance with the immortality theorem. The load releases energy; in the third stage, when the power semiconductor switch is still off, the residual magnetic flux energy stored in the primary side of the coupled inductor is charged in accordance with the law of magnetic flux immortality. 5. High efficiency and high boost ratio converter with reduced switching withstand voltage performance as described in item 1 of the scope of patent application, in which the primary side circuit, secondary side circuit and tertiary side circuit are combined to reduce switching withstand voltage performance, Limit the maximum voltage on the primary side 28! 239136; the combination is based on bismuth + A ^ 7 8 You connect the positive side of the primary side of the coupled inductor · Connect the negative side of the tertiary side of the switching inductor The negative terminal and work ', + —conductor switch and pole contact are connected to the negative terminal of the tertiary-side circuit capacitor, the output terminal of the tertiary-side circuit diode and the positive $ -contact of the tertiary-side circuit capacitor are connected to the light-on inductor 2. The positive terminal of the secondary side and the negative terminal of each of the secondary circuit circuits. 6. ^ The N-efficiency southern boost ratio converter with reduced switching withstand voltage performance as described in item i of the scope of the patent application, where the DC input voltage source is a storage battery f, a solar cell, a DC wind turbine, and an AC wind turbine. The entire φ current of the motor is a DC power supply as a power supply. 7 ·: The step-up ratio converter with reduced return voltage efficiency as described by the member of Shen Jingshili's range, with DC input voltage source, can use two or more different power supplies, Control the ratio of the input power of the power supply to improve the output power of the overall DC power supply. 8 · A high-efficiency, high-boost converter with reduced switching withstand voltage performance, which includes W ~: DC input circuit ·· DC input voltage and input filter capacitor are constructed, and the DC input voltage is connected in parallel with the filter capacitor , Can reduce the DC input voltage ripple; primary circuit ·· a coupling inductor primary side and a power semiconductor switch; the coupled inductor primary side and the power semiconductor switch are connected in series' by the power semiconductor switch on / off control coupling inductance Energy storage and release on the primary side; Primary circuit ... One coupling inductor secondary side, one diode and 29 1239136 capacitors; the secondary side of the coupling inductor is connected in series with the diode, and then different Parallel capacitors; a tertiary circuit: a coupled inductor tertiary side, a diode, and a capacitor; the tertiary side of the coupled inductor is connected in series with the diode, and then the same parallel capacitor; an auxiliary circuit: a capacitor, a It consists of an inductor and a diode; the connection method is that the capacitor, the diode and the inductor are connected in series; Current output circuit: a diode, an output filter capacitor and a load; the diode is connected to the positive end of the filter capacitor, and the filter capacitor is also connected in parallel with the load. A closed loop control mechanism: the voltage command and the DC output voltage The feedback comparison produces an error value. After proportional integral control, pulse width modulation and driving amplifier circuit, the output is a driving signal with adjustable duty cycle ratio, which triggers and cuts off the power semiconductor switch. It is characterized by a high boost ratio. And make full use of the voltage value established on the secondary side of the coupled inductor and the tertiary side of the coupled inductor to greatly improve the DC output voltage level; use the three-winding coupled inductor to improve the utilization rate of the high-frequency magnetic element iron powder core; reduce the switching resistance Voltage efficiency can reduce the withstand voltage specifications of the power semiconductor switch of the primary circuit. You can choose a MOSFET with a lower on-resistance to reduce the conduction loss; the output terminal can omit the filter inductor; the diode used in the DC output circuit is low voltage, low Schottky diode with on-voltage, which can reduce the conduction loss; Current, high-voltage side low current characteristics, can fully use the specifications and capacity of components, so the efficiency is higher than conventional circuits; the diode 1239136 used in the auxiliary circuit is a low voltage, low on-voltage Schottky diode, which can reduce the conduction loss 1 loss; the capacitance of the auxiliary circuit makes the converter have the function of further increasing the boost ratio; the combination of the capacitance of the auxiliary circuit and the series connection of the diodes has the function of reducing the voltage surge caused by the leakage inductance on the line; the auxiliary The combination of the capacitor, diode and inductor series of the circuit has the function of reducing the peak value of the diode current of the DC output circuit and averaging the current. 9. The high-efficiency and high-boost ratio converter with reduced switching withstand voltage performance as described in item 8 of the scope of patent application, where the capacitor of the DC input circuit is made of general electrolytic capacitor or super capacitor, which can absorb high-frequency harmonics. Constituent of the wave energy, stabilize the DC input voltage. 10. The high-efficiency and high-boost ratio converter with reduced switching withstand voltage performance as described in item 8 of the scope of the patent application, wherein the combination of the primary circuit, the secondary circuit, the tertiary circuit and the auxiliary circuit has a reduced switch The withstand voltage performance limits the maximum voltage of the primary circuit; its combination is that the positive terminal of the primary side of the coupling inductor is connected to the negative terminal of the auxiliary circuit capacitor, and the positive terminal of the auxiliary circuit capacitor is connected to the auxiliary circuit diode output terminal connection The negative terminal of the third side of the inductor, the negative terminal of the primary side of the coupling inductor is connected to the power semiconductor switch and the drain contact to the auxiliary circuit diode input terminal and the negative terminal of the auxiliary circuit inductor, and the positive terminal of the auxiliary circuit inductor is connected The negative terminal of the tertiary-side circuit capacitor, the output terminal of the tertiary-side circuit diode, and the positive-terminal contact of the tertiary-side circuit capacitor connect the positive end of the secondary side of the coupling inductor and the negative-terminal contact of the secondary-side circuit capacitor. 11. The high-efficiency, high-boost converter with reduced switching withstand voltage performance as described in item 8 of the scope of the patent application, where the DC input voltage source is a power storage 31 1239136 battery, solar cell, DC wind turbine and AC wind The generator is rectified into a DC power source as a power supply. ΐ2. = High efficiency and high boost ratio converter with reduced switching withstand voltage performance as described in item 8 of the scope of patent application, where the DC input voltage source can use two or more different power supplies to control the power supply Input power ratio to increase the overall DC power output. 32