CN205622506U - Accurate Z source converter of inductor type that takes a percentage - Google Patents

Abstract

The utility model provides an accurate Z source converter of inductor type that takes a percentage, be 1 including direct -current input power, the turn ratio: (I) n (i) transformer (i) T (i)), first diode (i) D (i) 1), second diode (i) D (i) 2), third diode (i) D (i) 3), first electric capacity (i) C (i) 1), second electric capacity (i) C (i) 2), first inductance (i) L (i) 1), switch tube (i) S (i)), fourth diode (i) D (i) 4), output capacitance (i) C (i) (i) out (i)) and load. The utility model discloses compare in flyback converter, accurate Z source converter etc. And have higher voltage gain, be applicable to the occasion of non - isolated form high -gain DC voltage transform.

Description

A Tapped Inductance Quasi-Z Source Converter

technical field

The utility model relates to the field of DC/DC converters, in particular to a tapped inductance type quasi-Z source converter.

Background technique

In recent years, due to the shortage of fossil energy, new energy power generation has developed rapidly. Fuel cells have attracted extensive attention from researchers because of their high power generation efficiency, low noise, and continuous operation. In view of the shortcomings of low output voltage, wide range, and slow dynamic response of the fuel cell, it is first necessary to add a DC/DC converter between the fuel cell and the load to output stable high-voltage direct current, and then output alternating current through the inverter. However, many step-up DC/DC converters are limited by the duty cycle, parasitic parameters and losses, and cannot achieve a large boost. For example, the flyback converter has a voltage gain of nD/(1-D), where n is the transformer Turn ratio, D is the duty cycle, but due to the influence of parasitic parameters, its gain is limited; another example is the quasi-Z source converter, its voltage gain is 1/(1-2D), which has a certain improvement compared with the Boost converter , but there is still room for improvement.

Utility model content

The purpose of the utility model is to overcome the deficiencies of the above-mentioned prior art, and propose a tapped inductance quasi-Z source converter.

The circuit of the utility model specifically includes a DC input power supply, a transformer with a turn ratio of 1:n, a first diode, a second diode, a third diode, a first capacitor, a second capacitor, a first inductor, Switch tube, fourth diode, output capacitor and load.

The specific connection mode of the circuit of the utility model is as follows: the positive pole of the DC input power source V _in is connected to the terminal with the same name on the primary side of the transformer. The opposite end of the primary side of the transformer is connected with the same end of the secondary side of the transformer and the anode of the first diode. The opposite end of the secondary side of the transformer is connected to the anode of the second diode. The cathode of the second diode is connected with the cathode of the first diode, one end of the second capacitor and the anode of the third diode. The cathode of the third diode is connected with one end of the first capacitor and one end of the first inductor. The other end of the first inductance is connected with the other end of the second capacitor, the drain of the switch tube and the anode of the fourth diode. The cathode of the fourth diode is connected with one end of the output capacitor and one end of the load. The output capacitor is connected in parallel with the load. The negative pole of the DC input power supply _Vin is connected to the other end of the first capacitor, the source of the switch tube, the other end of the output capacitor and the other end of the load.

Compared with the prior art, the utility model circuit has the advantages that: compared with the traditional flyback converter (its output voltage is ) and a quasi-Z source converter (whose output voltage is ) and other DC/DC converters, in the case of the same duty cycle and input voltage, have a higher output voltage, the output voltage is Under the same input voltage and output voltage conditions, the circuit of the utility model can raise the low-level voltage to a high-level voltage only with a small duty cycle, and the input and output common ground, continuous input current, etc., so the utility model The circuit has a very wide application prospect.

Description of drawings

Figure 1 is a structural diagram of a tapped inductance quasi-Z source converter.

Figure 2 is a voltage and current waveform diagram of the main components of a switching cycle.

Fig. 3a and Fig. 3b are circuit modal diagrams of different stages in a switching cycle.

Fig. 4 is the waveform diagram of the gain V _out /V _in of the utility model circuit, the flyback converter and the quasi-Z source converter changing with the duty ratio D in the example.

detailed description

The utility model will be described in further detail below in conjunction with the embodiments and accompanying drawings, but the implementation of the utility model is not limited thereto. It should be noted that, if there are any processes or parameters that are not specifically described in detail below, those skilled in the art can understand or implement them with reference to the prior art.

The basic topological structure of the utility model and the reference directions of the voltage and current of each main component are shown in Fig. 1 . For the convenience of verification, the devices in the circuit structure are regarded as ideal devices. The drive signal v _GS of the switching tube S, the current i D1 of the first diode D ₁ , the current i _D2 of the second diode D ₂ , the current i _D3 of the third diode D ₃ , the current i _D 4 of the fourth diode D ₄ i _D4 , excitation inductance L _m current i _Lm of transformer T, first inductance L ₁ current i _L1 , second inductance L ₂ current i _L2 , first capacitor C ₁ voltage V _C1 , second capacitor C ₂ voltage V _C2 The wave form is shown in Figure 2.

(1) During the t ₀ ~ t ₁ stage, the modal diagram of the converter at this stage is shown in Figure 3a. The driving signal v _GS of the switch tube S changes from low level to high level, and the switch tube S is turned on. The first diode D ₁ is turned on under forward voltage, and the second diode D ₂ , third diode D ₃ and fourth diode D ₄ are turned off under reverse voltage. The DC input power supply V _in and the second capacitor C ₂ charge the excitation inductance L _m of the transformer T through the switch tube S at the same time, and the first capacitor C ₁ charges the first inductor L ₁ through the switch tube S. In addition, the output capacitor C _out supplies power to the load.

(2) During the t ₁ ~ t ₂ stage, the modal diagram of the converter at this stage is shown in Fig. 3b. The driving signal v _GS of the switch tube S changes from high level to low level, and the switch tube S is turned off. The first diode D ₁ is cut off under reverse voltage, and the second diode D ₂ , third diode D ₃ and fourth diode D ₄ are turned on under forward voltage. The DC input power supply V _in and the excitation inductance L _m of the transformer T simultaneously charge the first capacitor C ₁ through the second diode D ₂ and the third diode D ₃ , and the DC input power supply V _in and the excitation inductance L of the transformer T _m simultaneously charges the second capacitor C ₂ , the output capacitor C _out and the load through the second diode D ₂ and the fourth diode D ₄ , and the first inductor L ₁ charges the second capacitor through the third diode D ₃ C ₂ is charged, and the first inductor L ₁ charges the first capacitor C ₁ , the output capacitor C _out and the load through the fourth diode D ₄ . In addition, the DC input power supply V _in , the excitation inductance L _m of the transformer T, the first inductance L ₁ and the second inductance L ₂ pass through the second diode D ₂ , the third diode D ₃ and the fourth diode D ₄ Charge the output capacitor C _out and the load at the same time.

The steady-state gain of the utility model circuit is derived as follows.

Since the average value of the voltages of the first inductance L ₁ and the excitation inductance L _m of the transformer T is zero within one switching cycle, the following relationship can be obtained.

$<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}\mathrm{<span\; class="notranslate">\; no</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; C</span>}\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; )</span>{\mathrm{<span\; class="notranslate">\; t</span>}}_{\mathrm{<span\; class="notranslate">\; o</span>}\mathrm{<span\; class="notranslate">\; no</span>}}<span\; class="notranslate">\; +</span>\frac{{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}\mathrm{<span\; class="notranslate">\; no</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; C</span>}\mathrm{<span\; class="notranslate">\; 1</span>}}}{\mathrm{<span\; class="notranslate">\; no</span>}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; t</span>}}_{\mathrm{<span\; class="notranslate">\; o</span>}\mathrm{<span\; class="notranslate">\; f</span>}\mathrm{<span\; class="notranslate">\; f</span>}}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 0</span>}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; )</span>$

V _C1 t _on -V _C2 t _off ＝0 (2)

And when the switch tube S is turned off, the output voltage V _out satisfies the following relationship.

V _out =V _C1 +V _C2 (3)

Simultaneously solving equations (1), (2) and (3) can obtain the relationship between the output voltage V _out and the DC input voltage V _in .

${\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; o</span>}\mathrm{<span\; class="notranslate">\; u</span>}\mathrm{<span\; class="notranslate">\; t</span>}}<span\; class="notranslate">\; =</span>\frac{\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; no</span>}\mathrm{<span\; class="notranslate">\; D.</span>}}{\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 2</span>}\mathrm{<span\; class="notranslate">\; D.</span>}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; d</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}}{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}\mathrm{<span\; class="notranslate">\; no</span>}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 4</span>}<span\; class="notranslate">\; )</span>$

The steady-state gains of the traditional flyback converter and the quasi-Z source converter are nD/(1-D) and 1/(1-2D) respectively (D is the duty cycle, n is the transformer turn ratio), when the turn ratio n When =2, the steady-state gain comparison diagram of the proposed circuit of the utility model and the flyback converter and the quasi-Z source converter is as shown in Figure 4, as can be seen from Figure 4, when the input voltage is 10V, the utility model proposed The circuit can be raised to about 106V only with a duty cycle of 0.32, while the other two converters require a larger duty cycle.

Claims (1)

1. a tap inductor type quasi-Z source converter, it is characterised in that include the transformator that direct-current input power supplying, the turn ratio are 1:n (T), the first diode (D₁), the second diode (D₂), the 3rd diode (D₃), the first electric capacity (C₁), the second electric capacity (C₂), first Inductance (L₁), switching tube (S), the 4th diode (D₄), output capacitance (C_out) and load；

Described direct-current input power supplying V_inPositive pole be connected with the Same Name of Ends on transformator (T) former limit；Described transformator (T) former limit different The Same Name of Ends of name end and transformator (T) secondary and the first diode (D₁) anode connect；The different name of described transformator (T) secondary End and the second diode (D₂) anode connect；Described second diode (D₂) negative electrode and the first diode (D₁) negative electrode, Two electric capacity (C₂) one end and the 3rd diode (D₃) anode connect；Described 3rd diode (D₃) negative electrode and the first electric capacity (C₁) one end and the first inductance (L₁) one end connect；Described first inductance (L₁) other end and the second electric capacity (C₂) Other end, the drain electrode of switching tube (S) and the 4th diode (D₄) anode connect；Described 4th diode (D₄) negative electrode with Output capacitance (C_out) one end and load one end connect；Described output capacitance (C_out) in parallel with load；Described direct current inputs The negative pole of power supply and the first electric capacity (C₁) other end, the source electrode of switching tube (S), output capacitance (C_out) other end and The other end of load connects.