TW200812211A - A high-efficiency current-source inverter using resonant technique - Google Patents

Abstract

In this invention, a high-efficiency current-source inverter using resonant technique is investigated to invert DC voltage into utility 60 Hz AC voltage. The traditional voltage-source inverter is operated by the pulse-wide-modulation (PWM) technique with an adequate designed inductance and capacitance filter to produce the fundamental AC sine wave. By this way, it limits the applied type of loads and the regulation ability under loads being varied suddenly. In the meanwhile, it has more waveform distortion and high-frequency harmonic components. This invention utilizes a controllable current source to supply the output capacitors and loads with high frequency switching for integrating the output sine wave voltage. In the proposed inverter, the four series diodes in the full-bridge circuit of traditional current-source inverter are omitted. All the switches and diodes in this circuit have the soft-switching property, i.e., zero-voltage switching (ZVS) or zero-current switching (ZCS). Moreover, the voltage stress of the switches is suppressed the source voltage such that it can use the low rated-voltage device with a small RDS(ON) to further reduce the conducting loss. In this mechanism, the maximum conversion efficiency is higher than ninety-seven percentages and the total harmonic distortion (THD) is less than two percentages. The waveforms of the experiment results are presented to demonstrate the performance of the proposed strategy via practical operation.

Description

200812211 IX. Description of the invention: [Technical field of the invention] The technical field of the invention includes the scope of power electronics, DC/AC conversion technology and green energy technology, but mainly consists of a DC power source (such as a fuel cell, a wind power, Solar energy, etc.) is used as an input power source to convert it to an AC power source to provide emergency power or general AC electrical load. The device controls the on-time of the clamp switch in each cycle by the error of the AC sinusoidal voltage command and the feedback voltage. The current source _ (Current Source) is generated by the coupled inductor, and the output capacitor is charged through the positive and negative cycle guidance of the full bridge switch, and the amplitude of the voltage rise or fall is adjusted to accumulate the AC sine wave output voltage. [Prior Art] At present, the products that convert DC power into 60Hz AC voltage on the market are roughly divided into two categories; the first type is an inverter applied to an AC motor, which uses a coil inductance characteristic of the motor to generate a sinusoidal pulse width modulation voltage waveform. Approximate sinusoidal current, this architecture cannot be applied to resistive or capacitive loads. Strictly speaking, inverters cannot supply general household appliances and computer products. The second category is the product launched for the shortcomings of the former. The typical product is the uninterruptible power equipment (UPS) as its structural diagram is shown in Figure 1 (a). Compared with the former class, the output increases the LC filter circuit of the inductor series capacitor, and increases the feedback control to make the output voltage fixed to overcome the load and input voltage variation. The biggest advantage of this type of product is that the architecture is simple and the cost is low, and the battery and Charge and discharge circuits to provide emergency power supplies other than utility power. At present, Taiwan manufactures UPS 200812211

Technology and production and sales share, such as Zi Da Electronics and Fei Rui, has been ranked among the best in the world. p makes such a % S dry characteristic still need to continue to improve. First of all, the lc wave circuit has many limitations: the first-point filter inductor runs through the entire output current, and considers the half-power frequency (-3dB) response in the bias-amplitude-amplitude circuit, and the inductance value and capacity are larger. The inductance value used by the UPS is approximately increased in the Grace filter inductance, which increases product weight and energy conversion losses. The second point is that the voltage W/edge applied to the inductor is the difference between the DC voltage and the output capacitor. The value is close to the minimum of the JE string peak, and the limited filter f sense value causes the positive=voltage peak turning point distortion to be high. The spectral component, even if the filter voltage is increased, cannot be avoided. This inductor provides filtering but at the same time limits the ability of non-linear loads to adjust for transient load changes. Third, a number of loads will jeopardize the drive circuit, such as half-wave rectifying load or high-inductive load, mainly due to the positive and negative half-cycle waveform symmetry of the LC filter and wave circuit, and the high-inductive load changing the frequency response of the second-order filter. The sinusoidal voltage is too low, and the DC voltage level must be increased. The system may be over-pressed and burned. Fourth, the voltage waveform distortion rate of non-resistive loads, commonly referred to as Total Harmonic Distortion (THD), is much higher than resistive loads. This is due to the fact that the previously designed second-order filter circuit cannot meet non-resistive loads such as capacitive, inductive and non-linear loads. The products of the flow device cannot provide all kinds of negative but inconvenient, and the users can distinguish the load in general. At present, the reverse load is not for the type of consumers, and can only buy the uninterrupted equipment by luck. — The 0-level capacity is a viable alternative. In addition, the switching loss of the switch increases with the increase of the switching frequency and thus decreases the efficiency of the 200812211 system. The application of the technology to the high power 1 (the barrier has begun to cite various flexible switching to reduce the PWM switching loss into the switching element] has been proved to be shapeable in several documents. Compared with the traditional sinusoidal switching frequency 'improvement of the wheel-out voltage waver Sinusoidal voltage, large adjacent eight, f-visible modulation voltage waveform 'current source reverse current voltage, can control the current source to charge the capacitor to accumulate sinus less such products, load and frequency change' but why the market runs All the up-and-vibration circuits are frequently cited techniques. The electric two are easy to generate an abnormality. (10) is the voltage value of the vibration. During the resonance process, the switch is turned on. Therefore, the voltage exceeds the rated value, that is, the semiconductor is immediately damaged but the resonant power m white vibrating road [1], [2]. Power supply, and then, = J rate is too low 'nearly half of the energy will flow back to the vibrating voltage source. The half-spectrum changing technique with voltage circuit is proposed. °° U reduces the switching stress of the switch and uses the pulse width adjustment. The two-transmission (10) shape [3]—[5]° is limited by the I-pulse period when the switch is turned on, so some resonant circuits are developed [6], [7] , the harmonic ft is limited to the _ conduction level Therefore, the switching frequency can be dizzy, and the Bayer cycle does not have to match the resonance time. Recently, some scholars have placed the wave inductor between the DC power supply side and the full-bridge inverter, as shown in Figure 1 (b Improve the dynamic response capability, form the current source backflow to improve the shortcomings of the traditional voltage source architecture. However, the current cutoff is the same as the system voltage, which is easy to endanger the switching components. It must be relatively upgraded, and the cost is greatly increased, which is not suitable for the application of this architecture in 200812211. Recently, the current source flexible switching architecture [8] has solved the bottleneck of this technology. This is applied to the solar power system to feed the commercial power to the reverse flow tm switch. The component has the effect of Zero Voltage Switching (ZVS) or Zero Current Switching (ZCS). The power factor of the feed to the mains is close to one, but the volume and quantity of the inductor still need to be reduced, and the switching frequency is low. (5kHz), causing high chopping output voltage. However, because I set e and count the purpose to directly feed the mains, it is not directly supplied to the load, so A clothing provides this The power quality of the system is better than the current voltage source inverter architecture. The follow-up mechanism of voltage clamping and flexible switching is proposed [9] ' applied to the two-phase AC motor driver, using the secondary side of the transformer for voltage clamping and Bypass current, the overall inductance value is reduced and the conversion efficiency is high. Basically, it has the characteristics of the current current source architecture. However, the inductance circulating current of the current source is too large, and the valley 1 is not easy to be small. In theory, the copper loss of the transformer is high. However, the MU loss is not calculated in the literature. In addition to the high voltage wave clutter, the biggest disadvantage of this architecture is that the switch needs to withstand four times the DC power supply voltage, the switching cost is too high and the driving object is the induction motor, which is not conducive to (4) product application. In addition, the f-low-frequency high-order spectral sinusoidal voltage inverter _, this architecture is very simple, using the geometric mean frequency (G_etric steal (10)

The characteristics of Mu·30 and the open circuit state, the voltage regulation rate has a good performance, but the resonant inductor capacity is too large, and the third harmonic component is too high. Voltage clamping and flexible switching effect At a $ + Xia Huashi's current source sinusoidal voltage inverter [11], [12], using low-excitation inductance is quite annoying M ^ 4 Wenbao-like primary side as current source inductance, will switch It has to withstand four times the DC voltage 湄 Φ μ μ a voltage drop is twice, its full bridge four switches have zero voltage and zero current cut # ^ 1 knife change. However, the four switches must be connected to a diode in series with 200812211, mainly to avoid short-circuit current of the output capacitor when the other half cycle is reversed, and also cause loop and conduction losses. In this architecture, the full-bridge switch is connected in series. The diode blocks the load feedback to the path of the DC power supply and cannot perform regenerative braking performance, which is a common disadvantage of most current source inverters. Secondly, the current source inductance value has reduced the capacity required for the aforementioned research, but to ensure zero current switching when the clamp switch is turned on, the inductor current must have a limited time control factor, and the operation is in the non-continuous area, causing the switch to switch. The wave current is high, and because of the low switching frequency, the output capacitor must be increased. Finally, in order to greatly increase the coupling coefficient, the transformer must use a sandwich winding method that is difficult to construct, and the secondary side winding current flows back to the power supply side. This energy is up to one-third of the output voltage. This high-circulation current is not introduced into the output end. , resulting in light load conversion efficiency is particularly low. The high-efficiency resonant current source inverter of the present invention utilizes a buck architecture in a DC converter to reduce the resonant inductor capacity, and uses a Flyback voltage clamping theory to limit the system voltage and to use a current source pair. The output capacitor and load directly switch to the high-frequency charge control, accumulating the sine wave voltage output to achieve the flexible switching characteristics of the zero-voltage or zero-current of all power semiconductor switching components, thereby improving the output efficiency of the inverter. The invention improves the principle and the control effect of the prior art as follows: 1. Using voltage clamping technology, coupled inductor current energy transfer and parallel spectral vibration technology in the resonant inverter, all power semiconductor switches and diodes have flexible switching Characteristics, the highest conversion efficiency is greater than 97%; 2. Using the voltage clamping technology of the present invention, the withstand voltage specification of all power semiconductor switching elements can be reduced, and the withstand voltage is approximately equal to or less than the input DC power supply 11 200812211 The voltage 'is much lower than the value The above documents are described. 3. Regenerative braking function: Since the full bridge switch of the invention does not need to be connected in series with diodes, and provides an uncontrolled brake diode circuit, the AC energy can be reversed to the DC power supply terminal, further clamping all systems. The voltage of the component. 4. The coupling inductor capacity and volume required by the present invention are smaller than the general current source architecture, and the coupled inductor can operate in a continuous current mode and can quickly adjust the current to supply the load, and can increase the switching frequency to help reduce the output capacitance valley. Hey. § When the power semiconductor switch trigger signal is turned on, if the secondary side winding current has dropped to zero before the trigger signal is turned on, it is a discontinuous current mode (DCM), so naturally forming conduction has zcs phenomenon; similarly, In the case of current continuous mode (CCM), the limited coupled inductor energy transfer effects still form conduction with ZCS characteristics. 5. The full-bridge anti-power semiconductor switch can omit the four series-connected ones of the conventional architecture, and use the parallel resonance characteristic to deal with the output voltage polarity. The parent is commutated without any switching elements, so the application can be omitted. The series-connected diodes used in the current-flowing descent system; 6. The round-out terminal can omit the conventional high-capacity series filter inductor. The current source directly charges the output load and the filter capacitor, so it can accept various inductive, capacitive, non-inductive The linear and transient load, and the output voltage waveform distortion rate and Fourier frequency 瑨 analysis are better than the traditional pulse width modulation architecture. Remarks: References [1] FJ Lin, RY Duan, and JG Yu5 ςίΑη ultrasonic motor drive 12 200812211 using a current-source parallel-resonant inverter with energy feedback/9Trans. Power Electron., vol. 145 no. 19 pp. 31 -42, 1999.

[2] R J. Lin, R. Y. Duan5 R. J. Wai and C. M. Hong, ULLCC resonant inverter for piezo-electric ultrasonic motor drive/5 IEE Proc. Electric Power Appl, vol. 1469 no. 5? pp. 479-487, 1999.

[3] L. Malesani, P. Tenti, P. Tomasin, and V· Toigo, “High efficiency quasi-resonant DC link three-phase power inverter for full-range

IEEE Trans. Ind. Αρρί, vol 31, pp. 141-147, 1995.

[4] V. V. Deshpande, and S. R. Doradla, “A new topology for parallel resonant DC link with reduced peak voltage/5 IEEE Trans. Ind, Appl, vol. 32, pp. 310-307, 1996.

[5] S· Chen, and T· A. Lipo, “A novel soft-switched PWM inverter for AC motor drivers/9 IEEE Trans. Power Electron., vol. 11? pp. 653-659, 1996· [6] P. C. Theron, and JA Ferreira, "The zero voltage switching partial series resonant converter/5 IEEE Trans. Ind. Appl9 vol 31, pp. 879-886, 1995.

[7] C. S. Moo, Y. C. Chuang, and C. R. Lee, “A new power - factor -correction circuit for electronic ballasts with series-load resonant inverter/5 IEEE Trans. Power Electron^ vol. 13, pp. 273-278, 1998· [8] R. Itoh, K. Ishizaka, H. Oishi and H. Okada, “Soft-switched current-source inverter for single-phase utility interfaces,” 13 200812211

Electron. Lett., vol. 37, pp. 1208-1209, 2001.

[9] H. Ishikawa, and Y· Murai, “A novel soft-switched PWM current source inverter with voltage clamped circuit/5 IEEE Trans. Power Electron., vol. 15? no. 6, pp. 1081-1087, 2000 .

[10] R·J· Wai, R·Y·Duan, J·D· Lee, and L·W· Liu, “High-efficiency fuel cell power inverter with soft-switching resonant technique/5 IEEE Transactions on Energy Conversion, Vol. 20, no. 2, pp. 485-492, 2005.

[11] R. J. Wai and R. Y. Duan? "High-efficiency power conversion for low power fuel cell generation system/5 IEEE Trans. Power Electronics, vol. 20? no. 4? pp. 847-856, 2005.

[12] R·J· Wai, R·Y·Duan, and L·W· Liu, “A current-source sine wave voltage driving circuit via voltage-clamping and soft-switching techniques/5 ROC Conference on Electrical Power Engineerings Part C-3, pp. 749-753, 2003.

[13] R. J. Wai and R. Y. Duan, “High-efficiency DC/DC converter with high voltage gain,” IEE Proc· Electric Power Applications, voL 152, no· 4, pp· 793-802, July 2005· 【Contents】 As shown in FIG. 2, the high-efficiency resonant current source inverter disclosed in the present invention includes a DC power supply 1〇1 slightly higher than the AC peak; the clamp circuit 102: consists of two Clamping switch 7], r2, two clamping diodes a, Z) 2., a brake diode D3 and a clamping capacitor c; a coupling circuit 14 200812211 103, by the primary side of the combined inductor Winding & and secondary winding /y, and a rectifying diode body; a resonant inverter circuit 104: by four full bridge switches 7; +, 7; -, 7; +, 7; A driving capacitor Cz and a resonant inductor A are formed, and a driving circuit 105 is responsible for feedback control and output of the driving signals of the six switches.

When the output voltage V is a positive half cycle of the sine wave, the current is clamped by the DC power source 101 via the clamp switch 7], Γ2, and the coupled inductor 7 of the coupling circuit 103; the primary winding & The full bridge switch Γα+, 7 of the inverter circuit 104_- charges the output capacitor Q. Similarly, when the voltage is to be a sine wave negative half-cycle output, the clamp switch 7 of the clamp circuit 102; 72 and the full-bridge switch 7 of the resonant inverter circuit 104; - and Γ / simultaneously trigger conduction, opposite to the output capacitance Charging; the clamp switches 7] and 72 of the clamp circuit 102 are responsible for switching the current source current at a high frequency, and the primary winding core of the coupling circuit 103 is interposed between the voltage of the DC power source 101, the clamp capacitor C of the clamp circuit 102, and the voltage L and Between the output capacitor Cz voltage % of the resonant inverter circuit 104, in principle, the current source must be used as a medium to limit the charging current of the output _ capacitor Cz, and the primary winding of the coupled inductor 7; & and the leakage inductance characteristics of the secondary winding & achieve the effect of flexible switching and voltage clamping of all power semiconductor switches; four full bridge switches in the resonant inverter circuit 104, respectively, at a frequency of 60 Hz and less than about Fifty duty cycles are turned on, full bridge switches C, 7; - responsible for guiding the current source current path of the positive half cycle, whereas the full bridge switch Γ / and Γ α - is the path of the negative half cycle; the resonant inverter circuit 104 The resonant inductor & and the output capacitor (^ form a set of second-order parallel resonance, using the characteristics of the inductor current behind voltage, the resonant capacitor A reversing the output capacitance Q 15 200812211 voltage Vf? polarity. The high efficiency resonant current of the present invention The timing and circuit operation modes of the source inverter are shown in Fig. 3 and Fig. 4 respectively. The above two _ 容容 segments are used as the principle. To simplify the circuit analysis, the 70-switch and the diode-on voltage are switched. It is easy to understand that 'proper nouns are not too long, the circuit belongs to the heart-shaped circuit 101.) Let's justify the direct description of the schema: Mode -: Time "~. Clamp switch. Turn on for a period of time', this mode starts after the clamp switch is turned on for a while, the voltage m is zero and the inductance C is the primary side winding current. From: "Source out, through clamp open_" and "2, clamp capacitor c. And the circuit formed by the inductive d-side winding m-resonant inverter = full-bridge switch C, 7Γ, and the output capacitor Q is charged. Capacitor C. The electric power is caused by the reverse bias voltage. Therefore, when the diode q and the off state are clamped and the polarity point voltage is positive, the voltage across the secondary winding 4 can be expressed as ω.

Ld.did, dt = VLd=ViN+Vc〇_v〇(1) The upper core is the input DC power supply voltage, the % is the output AC voltage, and the second (4) capacitor q voltage on the right side of the equal sign can be improved—the secondary side winding Group: The initial rate of climb of the current core, the slope of the middle section is reduced by the decrease of the voltage '〇: Therefore, the current chopping component is not too high, and the smaller sense value can be designed—the secondary winding Z and effectively reduce the clamp switch. Conduct responsibility cycle and conduction loss. In addition, the clamp switch J; and the cross-pressure ~ and 々2 of A are respectively, (2. a) = Vc〇- VD2 16 200812211 VT2 = Vco ~~ VDl According to the above formula, the clamp can be obtained (2.b) And the cross-pressure % and % of a are as follows (3.a) (3.b) (4) VD\ = vc〇~~ Vr2 VD2 = Vco ^ Vri Output AC voltage V. The countable tube is _ ct\ . ^ ^ v〇Uld-iLL-i〇, -dt , which is the AC load current. In this mode, L is the resonant inductor 々 current 2 clamp capacitor c; electric zero; ^ mode:: Time "~, 2) clamp diodes A, A conduction vanes = capacity to near zero volts, according to equation (3.a) and formula (3.b, 1 and A across the pressure by the reverse bias To zero volts, then ^^^' form a two-clamp diode zero-voltage switching conduction. At this time, the clamp 2 is still in the on state, forming two sets of switches = parallel to each other, and sharing the flow-to-round capacitance Q's charging mode 3: time (, 2~, 3) clamp switch and G trigger signal cutoff 2 system trigger signal cut off, full bridge switch π and Μ 10:, people' box mouth inductance primary side winding core limited Leakage sense freewheeling factor, re-circulation through A, c Liu, clamp capacitor c, output capacitor: filling = in Q << Q, so when clamping capacitor c. Electric core. Fast rise: V〆, There is a U-up. According to equations (2a) and (2b), the voltage at the = terminal is equal to the voltage across the clamp diode plus "j power plant hard v, when the voltage rises gradually, Clamp switch cut-off = 17 200812211 Zero-voltage switching characteristic, clamp capacitor C at the same time; fully absorb the coupling inductance 7; the energy of the primary side winding leakage, and then to the output capacitor during the mode of the next cycle仏, the clamp capacitor voltage % can be expressed as

T2 < t < t4 (5) At this time, the voltage across the primary winding 4 can be expressed as VLd=VIN-Vc〇^V〇(6). According to the above formula, the primary winding core of the coupled inductor is at the polarity point. For the positive φ voltage, the induction to the secondary winding inductance & also the same situation, so the rectifying diode of the coupling circuit is still reverse biased, the secondary winding & no current path. Mode 4: Time (ί3~ί4) coupled inductor secondary side current begins to conduct This mode starts from the clamp capacitor G voltage temple, calculated according to equation (6), the voltage polarity of the coupled inductor primary side winding 4 begins to invert, in non-polar The point is a positive voltage, and the induction to the secondary winding inductance Z/ is also the same, so the rectifying diode of the coupling circuit is in a forward state. According to the law of magnetic flux immortality, the secondary winding & begins to generate current. During this period, the secondary side winding 4 current flows into the resonant inverter circuit along with the primary winding core, and the relationship can be expressed as + ^/ Ζ'/ (7) where the highest value of the current ^, the two currents V and G are one long, the current mode stops at the current & zero, and the current & reaches the highest point. Because of the clamping capacitor C; the leakage inductance energy can be fully absorbed, and the magnetic flux is released by the secondary winding, the leakage inductance has little effect on the system. To simplify the analysis, the leakage inductance energy is not considered [13]. Let the number of turns of the coupled inductor and the secondary winding 18 200812211 be % and τν2 respectively, then the turns ratio ^ can be expressed as (8) Μ仏 During this mode, the secondary winding voltage -VZ/ is equal to V, and can be reversed once. The voltage of the side winding 4 & is vLd = ^ · (9) According to Kirchhoff's voltage law, the equation of this mode can be expressed as follows: VIN ^Vco + —~Vo =0 (10) η

Vco=VIN + (--!)Vo (11) η Since % is AC voltage, add absolute value to simplify analysis (12) The second term of the above equation is negative, because the clamp capacitor voltage % crosses the clamp switch At the end, the highest voltage value occurs when the output AC voltage & zero, • The switch financial specification can be obtained as

Vn(max) ~ Vr2(max) ~ ^IN (13) Therefore, the clamp switch of this architecture has the same withstand voltage as the input voltage, and the same four switches of the whole bridge 7; +, 7; -, Γ / and 7; _, Because the output is a capacitor and has the voltage clamping performance of the flywheel diode, the switching withstand voltage and the output AC voltage V. the same. Mode 5: Time (ί4^ί5) Current 9 starts to drop from the highest point. When the primary winding current & is reduced to zero, the coupled inductor energy is transmitted through the secondary winding current // to the output capacitor, so the current is Most 19 200812211 The high point began to decline. This mode is only when the trigger signal of the clamp switch ii, r2 is turned on. Mode 6: Time (〖5~/〇) clamp switch 7; Γ2 trigger signal conduction

At this time, the clamp switch 7;, Γ 2 trigger signal is turned on. If the secondary side winding current b has dropped to zero before the start of this mode, it is a discontinuous current mode (DCM), so naturally forming conduction has a ZCS phenomenon. . Similarly, if it is a continuous current mode (CCM), the leakage inductance of the primary side winding 4 and the energy transfer of the windings on both sides are limited, and the same electrical characteristics as in the fourth mode, the conduction is still formed and has the ZCS characteristic. In addition, 9 outputs an AC voltage 'about 90 degrees electrical angle after the current k of the vibrational inductance A of the vibrating part 9 of the vibrating body. Therefore, when the output AC voltage is near zero volts, the current L is the highest value, and the output can be extracted. The energy of the capacitor is used to complete the zero-crossing commutation. This process does not need to be switched and controlled. Therefore, the series diodes commonly used in general current sources can be omitted, and the high-gain voltage of the second-order resonance occurring during no-load is avoided. The frequency should be avoided 60 Ήζ. In order to ensure the success of the commutation, to avoid omitting the short-circuit current of the flywheel path caused by the series diode, the resonant inductor current energy must be higher than the output capacitor potential energy, which can be expressed as

L X^LL(max)

(14) In the general current source architecture, the series diode of the full-bridge switch blocks the load feedback to the DC power supply path, and must be used as an AC resistance brake circuit. When the output voltage is higher than the DC power supply voltage, the brake diode A of the present invention naturally conducts and provides an energy feedback path, which occurs when the load is the flywheel inertia of the AC motor, and the inductive load changes the resonant frequency 20 200812211 High voltage; the brake diode draws its energy to the DC supply voltage absorption. In addition to clamping all the switching voltages, the regenerative braking function effectively utilizes the source-to-load energy to improve energy efficiency. As can be seen from the above description, most switching diodes and switches have both ZCS and ZVS characteristics when turned on and off, so that the circuit of the present invention can achieve high conversion efficiency in theoretical analysis. While the present invention has been disclosed in its preferred embodiments, it is not intended to limit the invention, and the invention may be variously modified and modified without departing from the spirit and scope of the invention. The scope of protection is subject to the definition of the scope of the patent application attached. [Embodiment] All power semiconductor switches of the main components of the present invention are selected from MOSFETs, numbered IRFP264, on-resistance, withstand voltage of 250V and rated current of 44A, and packaged in the form of TO-247. According to the equation (13) V, the highest financial specification of the switch is applied. The purpose of the embodiment of the present invention is to control the output voltage to a peak value of 156V, and convert it into an effective value of 11〇v, and set a power supply with a rated output specification of AC 110V60Hz 500W. specification. The other parameter design and component selection of the present invention are as follows: DC input voltage: 170V AC output voltage: AC UOV 60Hz Switching frequency: 50kHz Momax inductor is one of the side winding core and the primary side winding ~:100 must be 200 must , 〆, secondary winding turns Μ and τν2: 8·5 and 12匝, core_EE55, 21 200812211 Turning factor k = 0.98 Clamp switch 7], Γ 2 and full bridge switch C, CCC : POWER MOSFET IRFP264 ^ Vds=250F ^ RDS{ON)=60mQ ^ ID=44A ^ TO-247 Output Capacitor Q and Resonant Inductance A: 6·8π and 1.03477 Clamp Capacitor C; : 0.04π Clamping Dipoles A, D2 and QC: SFA1604G and SFA1608G Resonant frequency: 60Hz Figure 5 shows the high-efficiency resonant current source inverter disclosed in the present invention. • 60Hz measured waveform of each component, Figure 5(a) shows the output voltage at no load and coupled inductor 7; The secondary winding & current Q, wherein the output voltage V is accumulated by the frequency 50 kHz high frequency switching according to the PI proportional integral method, the chopping voltage of the trace high frequency component is improved, and the current ^ is small. The output voltage V, the region near the zero value, is completely provided by the resonant inductor A, and the current G is almost zero, which proves that the energy-loss pole of the high-efficiency resonant current source inverter of the present invention is unloaded. low. Figure 5(b) shows the waveform of the output voltage % and the resonant inductor 4 current k. The resonant inductor A has an inductance value of 1.034//, and the current L peak value is 0.39A. It is known that its capacity is 30.5VAR, although the inductance value is high. But the actual volume is quite small. In Fig. 5(c), the output capacitor Q terminal voltage of the output power is 400 W and the primary side winding 4 current Q. In order to simplify the analysis of the average value of the primary winding current at steady state, the clamp capacitor voltage is not considered at this time, according to the Khähoff voltage and current law.

Vo = VLL ~ ^LL ! dt- VCL (15) and h = z'cl + hL + K (16) 22 200812211 The output voltage V is AC 110V 60Hz, so ' can be expressed as 156sin377p flow through the load and (assumed to be 30ω), output capacitor G and resonant inductor 4 currents C, z cz and ζ can be expressed as respectively, K = 156sin377i _ ^ . :---= 5.2sin377iA κ (17) 156sin377i · ^CL =---- =CL . 156 cos377i = 0.39 sin ( 3771 + 90°) AA CL (18) 156sin377i A hL a r =0.39sin(377^-90°) A all (19) Therefore, the output voltage V is near the zero value , the current flowing through the load ζ; zero, the current 匕 and Q are the same but the phase difference is 180 degrees, so the voltage commutation energy of the output capacitor Q can be completely provided by the resonant inductor 4, so there is no need to input the commutator = provide commutation The required current path, the coupled inductor I - the current of the secondary winding 4 ~ is almost zero, only the energy loss of the resonant process needs to be supplied. After the commutation is completed, during the on-time of the clamp switch Γ1 and Α, the charging current is proportional to the e〇s function according to equation (18) = output, so the current core is the second ''output voltage~ peak value only needs Supply load and current, this area is related to the weight of the load. In Figure 5(d), the voltage of the full-bridge switch c is 2, the low-frequency switching is performed on the bridge switch, and the non-switching loss/crossing of the full-bridge switch exhibits a zero-voltage state at both ends, and the full body provides the back. The output is the capacitor 'plus the flywheel two-pole switching voltage +, the voltage of the voltage is close to the current & the figure shows that the clamping voltage t has a voltage clamping characteristic when it is connected across the cut-off, because the clamped capacitor is electrically connected to the two ends of the switch' The highest voltage value occurs at output AC 23 200812211 voltage V. When zero, the voltage required by the waveform display switch corresponds to the derivation equation (13). As shown in the circuit of Figure 5, the resonant inverter circuit has effectively controlled the zero-crossing waveform of the output voltage, and ^ the intersection:: near the domain, (4), no current is passed. The high-efficiency spectral current source of the present invention has all the power semiconductor switches with the same voltage and voltage as the input voltage, and the voltage withstood is less than or less than the power supply I, and the voltage is better than the conventional inverter [11 j.

夂-Ut r high-efficiency resonant current source inverter, the measured waveform of each element, in which the continuous mode of the inductor, the secondary winding current shape, the influence of the leakage inductance on both sides of the winding When clamping the capacitor, according to equation (6), the combined polarity of the secondary side starts to be inverted, and the positive polarity to the second set of V at the non-polar point is also the same, because the rectified two state of the combined circuit. According to the law of magnetic flux immortality, a 遐 冯 冯 Feng 偏 偏 此 此 此 此 此 此 此 此 此 此 此 此 此 此 此 此 此 欠 欠 欠 欠 欠 欠 欠 欠 欠 欠 欠 欠 欠 欠 欠 欠 欠 欠 欠 欠 欠 欠 欠 欠One (7) produces a change. Its crossover change: the current relationship of the group is based on the equation and the secondary side winding is as shown in Fig. 6(b)—the current of the secondary side winding ECG winding 4. The drop and the two 'v Drop 'and Figure 6 (4) is the voltage of the secondary current diode ~ rise. Item 6 (d) is the rectifier diode voltage % waveform ^^ wire, shown by the waveform of the inspection, the whole fruit 'and zero current at the same time Both the soil = pass and the cut-off day have flexible switching efficiency vD / current flow switching due to high voltage oscillation; in addition, the surge voltage of the rectified diode is added to the cushioning circuit 24 200812211 (snubber) and numerical simulation > The 660 volts has been reduced to 56 volts, and the surge voltage can be reduced by the damper circuit to reduce the diode withstand voltage specifications. Figure 6 shows the voltage vn and current ζ·η waveform of the clamp switch η, and the clamp switch Flexible switching effect during turn-on and turn-off, plus power half with low withstand voltage specifications The conductor switch' can improve the conversion efficiency of the present invention. Figure 7 shows the waveform of the high-efficiency resonant current source inverter of the present invention in no load and various loads, and the current measured waveforms, respectively. Fourier frequency analysis to calculate the total harmonic distortion rate (THD). Figure 7 (sentence is no wear, where the fundamental frequency (60Hz) is 4〇6dB almost the same as the RMS rms' total spectral distortion rate (THD) ) is 1.0%. Figure 7 (b) load is a nonlinear rectifying load (i? = 100Q, C = 47 〇 MF), where the value of the fundamental frequency (6 Hz) is repeated, the total harmonic distortion rate (Caf) ) is 18%. Figure 7 (4) load is inductive load (the measured total harmonic distortion rate is 13.92% higher than the international standard value of 5%. Figure 7 (4) is Figure 7 (c) Inductance: negative

The output voltage pattern after the carrier shape is improved. If the output capacitor ^ is connected in parallel with the 12.5W capacitor 'to reduce the backward virtual power required to fully supply the inductive load ^ total ripple distortion (THD) to Q · 9 8 %, solve the waveform distortion caused by the supply of inductive load problem. ® 7(e) is a voltage waveform diagram of the 36Ω resistive load that is instantaneously loaded by the inverter. According to the experiment, the output voltage d value is only slightly distorted. The waveforms of FIG. 7 refer to the south efficiency resonant current source inverter disclosed in the present invention, which can accept various inductive, capacitive, non-linear and instantaneously varying loads, and the total spectral distortion rate of the wheel voltage waveform. And Fourier spectrum analysis are better than the above reference 0 25 200812211 FIG. 8 shows a conversion efficiency diagram of the high efficiency resonant current source inverter disclosed in the present invention and reference [11], which shows the high efficiency of the present invention. The resonant current source inverter has a conversion efficiency higher than 97%, which is superior to the reference [11] at light load and heavy load, especially at light load, using resonant commutation technology and secondary winding & current Importing the output terminal greatly reduces the circulating current component of the switching current, so the conversion efficiency can be increased by up to 8%. The invention realizes the high-performance current sinusoidal voltage conversion circuit through the circuit implementation, and the comprehensive features are as follows: φ 1 · The current source is controlled by the surface-inductance first-secondary energy transfer mode, so that all the semiconductor switches and the diodes have Flexible switching characteristics, the maximum conversion efficiency is greater than 97%, and after the various load tests, the total harmonic distortion (THD) of the inverter of this architecture is less than 2%; 2. The voltage semiconductor technology can be used to reduce the power semiconductor The withstand voltage specifications of the switching components, the voltages of all the switches are about equal to or less than the power supply voltage; 3. The coupled inductor capacity and volume are smaller than the general current source architecture, and all the energy is transmitted to the output terminal, no circulation problem; • 4·coupled inductor operation In the continuous current mode, the switching frequency can be increased to reduce the sense value, and the switch still has a flexible switching effect; the circuit is implemented as a component flexible switching characteristic. 26 200812211

Table 1 Flexible switching characteristics of main components Zero voltage switching (zvs) Zero current switching (zcs) Component symbol turn-on turn-off turn-off 〇〇〇T:, Ta-, Tb+, Tb- 〇〇〇〇D\, D2, D3 〇〇 〇〇Df 〇〇〇〇27 200812211 [Simplified Schematic] Figure 1 shows a schematic diagram of a conventional sinusoidal voltage inverter. Figure 2 is a block diagram showing the high efficiency resonant current source inverter circuit disclosed in the present invention. Fig. 3 is a timing chart showing the waveforms of the high efficiency resonant current source inverter disclosed in the present invention. Fig. 4 is a view showing the operation mode of the high efficiency resonant current source inverter disclosed in the present invention. • Figure 5 shows a 60 Hz measured waveform of each component of the high efficiency resonant current source inverter disclosed in the present invention. Fig. 6 is a graph showing the measured waveforms of the high frequency operation of the components of the high efficiency resonant current source inverter disclosed in the present invention. Figure 7 is a graph showing the measured waveforms of the high efficiency resonant current source inverter disclosed in the present invention at no load and various loads. Figure 8 is a graph showing the conversion efficiency of the high efficiency resonant current source inverter disclosed in the present invention and the reference [11]. [Description of main component symbols] 101: DC power supply 102: Clamp circuit 103: Coupling circuit 104 • Spectral inverter circuit 105: Control and drive circuit η: Power semiconductor switch of clamp circuit (referred to as clamp switch) 28 200812211 G : Clamping Power semiconductor switch of circuit (referred to as clamp switch) C, CC and 4: power semiconductor switch of resonant inverter (referred to as full bridge switch) 7; transformer with high excitation current (referred to as coupled inductor) moxibustion: coupled inductor 7; Coupling coefficient (referred to as coupling coefficient) 4: coupled inductor 7; primary winding (referred to as primary winding) 4: coupled inductor 7; secondary winding (referred to as secondary winding) A: resonant inverter circuit Resonant Inductance • A: The first clamped diode of the clamped circuit A: The second clamped diode of the clamped circuit A: The brake diode of the clamped circuit: the output of the rectified diode resonant inverter circuit of the coupled circuit Capacitor Q: Capacitor Capacitor for Clamping Circuits 29

Claims (1)

200812211 X. Application Scope: 1 A high-efficiency resonant current source inverter consisting of a clamp circuit consisting of two clamp switches, two clamp diodes, a brake diode and a clamp capacitor. Is to control the current and rebound energy of the coupled inductor; a coupling circuit: consisting of one of the coupled inductor, the secondary winding and a rectifying diode 'the primary side winding limits the current of the DC voltage source' and stores it during conduction The energy is transmitted to the secondary side winding through the coupled inductor and continues to be discharged to the resonant inverter circuit. A resonant inverter circuit is composed of four full bridge switches, an output capacitor and a resonant inductor, mainly guiding the primary side. The winding current is output to the output capacitor to accumulate the AC output voltage; a control drive circuit: the closed-loop control of the sine wave command voltage and the output voltage, and finally the driving signals required for the two clamp switches and the four full-bridge switches; The inductor circuit is a buffer circuit between the input DC power supply and the resonant inverter circuit, and the voltage difference between the two voltage sources is coupled across the coupling The inductor is presented as a current source; the current source current flows into the resonant inverter circuit via the two symmetrical clamp switches and the clamped diode combination path of the clamp circuit; the resonant inverter circuit directs the current from the DC power supply terminal Lead to the output capacitor, and control the voltage polarity of the output capacitor to generate an AC voltage; in addition to starting the current of the inverter circuit, the clamp circuit is clamped with the two winding characteristics of the coupled inductor, so that all power semiconductor switches and two The polar body has flexible switching characteristics; the clamping circuit can reduce the financial voltage specification of the power semiconductor 30 200812211 switch, and its withstand voltage specification is equivalent to the input power supply voltage; the capacity and volume of the coupled inductor are smaller than the current current source architecture, and the load is changed according to the load. Quickly adjust the current; the output can omit the conventional series of filter inductors' and use the resonant inductor to assist the output voltage polarity commutation; allow the supply of various inductive, capacitive, nonlinear and transient loads. 2. The high efficiency resonant current source inverter according to claim 1, wherein the clamping circuit can absorb the leakage inductance energy of the primary winding of the coupled inductor, and the energy is absorbed and can be transmitted to the output terminal in the next cycle. The coupling inductor used in the present invention can accept a high leakage inductance transformer, and is not limited to the sandwich winding method using the coupling coefficient, and can be completed by using a conventional rain winding to separate the winding method. For example, the patent claims the high-efficiency resonant current source inverter described in item 1, wherein the resonant reverse current H circuit adopts a full-bridge architecture, and the power semi-conductor switch is used to " The 50 GHz frequency of the 50-degree duty cycle is turned on, and the excitation inductance is applied to the output capacitor terminal. The wheel-out voltage is matched with the resonant inductor commutation process. 'The four full-bridge switch diversions are not switched by the resonant inverter. The polarity of the capacitor voltage is opposite, forming the short-circuit current of the output capacitor. Therefore, omitting the one-body series that must be connected in series with the full-bridge switching architecture of the self-use I source is the 90-degree characteristic of the voltage after the de-energized voltage is used when the wheel-out voltage is close to zero. , electric power 4 by the hunting vibration inductor current does not take the charge of the output capacitor and ~ peak region 'the polarity of the reversal, in this zero voltage crossover zone 2 to complete the AC voltage must be, when the output voltage polarity changes, S kg has all The bridge switch is cut as described in the patent application scope item [the high = only, conduction; the sheep shouts ^ flow source reverse flow 31 4 200812211, in the voltage clamp circuit, the brake diode mainly provides the output voltage is higher than the DC power supply The energy feedback path of the pressure occurs when the load is the flywheel inertia of the AC motor and the inductive load changes the high frequency caused by the resonant frequency; the brake diode draws its energy to the DC power supply voltage terminal, except that all switches can be clamped Voltage and efficient use of source-to-load lift-up energy. 32