CN104092396B - A kind of double Boost inverter of single inductance and control method thereof - Google Patents

Abstract

The invention discloses a kind of double Boost inverter of single inductance, two Boost boosting units share a boost inductance, can effectively promote the efficiency of traditional double Boost inverter and reduce the volume of inverter；Propose the control method of the double Boost inverter of a kind of single inductance simultaneously, control the switching tube alternation in sinusoidal wave positive and negative half period respectively of two Boost boosting units, reduce switch tube voltage, current stress, reduce inductive current ripple, reduce the conduction loss of the internal circulation of changer.

Description

A kind of double Boost inverter of single inductance and control method thereof

Technical field

The invention belongs to Technics of Power Electronic Conversion technical field, be specifically related to a kind of double Boost inverter of single inductance and control method thereof.

Background technology

New forms of energy owing to being affected by factors such as environment, its output voltage range width, need by buck inverter it is inverse Become available stable alternating voltage.Traditional inverter, when DC voltage is less than the alternating voltage of output, needs in inversion The prime of device adds booster converter to reach boost function.But two-stage type power conversion makes system structure complicated and affects efficiency. Boosted by Industrial Frequency Transformer, there is the defects such as Industrial Frequency Transformer is heavy, bulky.

The inverter of single stage power converter is conducive to the lifting of power density and efficiency, single stage type inverter only to have power stage One-level, efficiency is high, the advantages such as volume is little.The inverter of double-boost converter, uses the two-way DC/DC of two groups of independent symmetrical Changer differential output, obtains pure sinusoid alternating voltage.Common modulation system is to make two groups of Boost respectively export a road The voltage of 180 ° of band direct current biasings of difference, obtains the ac output voltage of lifting press through differential output.Under this modulation system The all power switch of changer are in high frequency modulated state in whole power frequency period, and inductive current is big, switch tube voltage is electric Stream stress is the biggest, causes inductor loss, switching tube on-state loss to increase with switching loss, and the most whole changer exists internal Circulation, is unfavorable for the lifting of efficiency.

Summary of the invention

The technical problem to be solved is: propose a kind of double Boost inverter of single inductance, two Boost boosting units Share a boost inductance, can effectively promote the efficiency of traditional double Boost inverter and reduce the volume of inverter；Carry simultaneously Go out the control method of the double Boost inverter of a kind of single inductance, control the switching tube of two Boost boosting units respectively at sine Alternation in the positive and negative half period of ripple, reduces switch tube voltage, current stress, reduces inductive current ripple, eliminates changer Internal circulation.

The present invention solves above-mentioned technical problem, adopt the following technical scheme that

The double Boost inverter of a kind of single inductance, including Boost boosting unit I, Boost boosting unit II, boost inductance, Switching tube I, the input of Boost boosting unit I is connected in parallel with the input of Boost boosting unit II, and Boost boosts The outfan of the outfan of unit I and Boost boosting unit II be connected in series after as the outfan of this inverter, inverter Outfan includes the first end, the second end, and Boost boosting unit I includes switching tube II, switching tube III；Boost boosting unit II includes switching tube IV, switching tube V；Described switching tube all includes input, outfan, control end, also include switching tube VI, Switching tube VII, connecting valve pipe VI between the first end and the positive pole of DC source of inverter output end, the of inverter output end Connecting valve pipe VII between two ends and DC power anode；Boost boosting unit I and Boost boosting unit II share one and rise Voltage inductance and switching tube I, wherein, one end of boost inductance, the outfan of switching tube I are all connected with the positive pole of DC source, The other end of boost inductance, the input of switching tube I all boost single with the positive pole of Boost boosting unit I input, Boost The positive pole of unit's II input connects.

Equal parallel diode between the input of switching tube, outfan, the anode of diode is connected with the outfan of switching tube, and two The negative electrode of pole pipe is connected with the input of switching tube.

In sinusoidal wave positive half period, controlling switching tube I and be in HF switch state, switching tube II, switching tube VII are in often Logical state, controls switching tube III conducting complementary with switching tube I；In sinusoidal wave negative half-cycle, control switching tube I and be in height Frequently on off state, switching tube IV, switching tube VI are in normal open state, control switching tube V conducting complementary with switching tube I.

Compared with prior art, there is advantages that

1, the double Boost inverter circuit of single inductance of the present invention shares a boost inductance and HF switch pipe, is conducive to improving merit Rate density, reduces the volume of inverter.The voltage stress making switching tube is less than traditional approach with the current stress of inductance, altogether With boost inductance L1 and HF switch pipe S1,.

2, application half cycle modulation method so that the switching tube of two Boost boosting units is in half cycle high-frequency work, by-pass switch Plumber's frequency switching state, decreases the switching loss of inverter.Simultaneously compared with traditional control method, reduce again conduction loss, Eliminate the inside circulation of changer.

Accompanying drawing explanation

Fig. 1 is the circuit diagram of the double Boost inverter of list inductance of the present invention.

Fig. 2 is the modulation system schematic block diagram of traditional double Boost inverter.

Fig. 3 is the modulation system schematic diagram of the double Boost inverter of list inductance of the present invention.

Fig. 4 is list inductance of the present invention double Boost inverter experiment drive waveforms.

Fig. 5 is list inductance of the present invention double Boost inverter experiment drive waveforms.

Fig. 6 is the double Boost inverter switching device tube voltage stress of list inductance of the present invention.

Fig. 7 is list inductance Boost inverter input and output voltage of the present invention and inductive current.

Detailed description of the invention

Below in conjunction with the accompanying drawings technical scheme is described in detail:

As it is shown in figure 1, the double Boost inverter of single inductance, including Boost boosting unit I, Boost boosting unit II, rise Voltage inductance L1, switching tube S1～S7, electric capacity C1, C2, diode D1～D7, the input of each switching tube, outfan it Between a diode all in parallel, the anode of diode is connected with the outfan of switching tube, the negative electrode of diode and the input of switching tube End connect, switching tube S6, S7 as the by-pass switch pipe of this inverter circuit, Boost boosting unit I include switching tube S2, S3, the input of switching tube S2 is as the input of Boost boosting unit I, the outfan of switching tube S2 and switching tube S3 Outfan connect, the input of switching tube S3 is as the first end of this inverter output end；Boost boosting unit II includes out Close pipe S4, S5, the input of switching tube S4 as the input of Boost boosting unit II, the outfan of switching tube S4 with open The outfan closing pipe S5 connects, and the input of switching tube S5 is as the second end of this inverter output end；Inverter output end Series capacitance C1, C2 between two ends；The positive pole of DC source Vin respectively with the outfan of switching tube S6, switching tube S7 defeated Go out end, one end of boost inductance L1 connects, the negative pole of DC source Vin respectively with outfan, the electric capacity C1 of switching tube S1 It is connected with the midpoint of C2 series circuit；The other end of boost inductance respectively with input, the Boost liter of Boost boosting unit I The pressure input of unit II, the input of switching tube S1 connect；The input of switching tube S6 and the first end of inverter output end Connecting, the input of switching tube S7 is connected with the second end of inverter output end.

Boost boosting unit I hereinafter referred to as Boost1 in the present embodiment, Boost boosting unit II hereinafter referred to as Boost2.

Common modulation system is the voltage making two groups of Boost respectively export road 180 ° of band direct current biasings of difference, through difference Dynamic output obtains the ac output voltage of lifting press.Boost1 Yu Boost2 is made to be simultaneously in pressure-increasning state, so four are opened Close pipe and be in HF switch state, as shown in Figure 2.By the corresponding logic that controls, the output voltage of two groups is met:

$V_{o1}\left(t\right)=V_{\mathrm{dc}}+\frac{1}{2}\×U_m\×\sin \left(\mathrm{wt}\right)---\left(1\right)$

$V_{o2}\left(t\right)=V_{\mathrm{dc}}+\frac{1}{2}\×U_m\×\sin (\mathrm{wt}-\mathrm{\π})---\left(2\right)$

$V_{\mathrm{dc}}\≥V_{\mathrm{in}}+\frac{U_m}{2}---\left(3\right)$

$V_{o1}=V_{o2}=\frac{1}{1-D}\×V_{\mathrm{in}}---\left(4\right)$

Wherein V_dcFor DC offset voltage, U_mFor expectation output voltage peak value, V_o1For obtaining the output voltage of Boost1, V_o2For The output voltage of Boost2, V_inFor direct current power source voltage.

Simultaneous above formula pushes away to obtain the change in duty cycle rule of Boost1 Yu Boost2:

$D_1\left(t\right)=\frac{\frac{U_m}{2}+\frac{U_m}{2}\×\sin \left(\mathrm{wt}\right)}{V_{\mathrm{in}}+\frac{U_m}{2}+\frac{U_m}{2}\×\sin \left(\mathrm{wt}\right)}---\left(5\right)$

$D_2\left(t\right)=\frac{\frac{U_m}{2}-\frac{U_m}{2}\×\sin \left(\mathrm{wt}\right)}{V_{\mathrm{in}}+\frac{U_m}{2}-\frac{U_m}{2}\×\sin \left(\mathrm{wt}\right)}---\left(6\right)$

So make the dutycycle of Boost1 Yu Boost2 respectively by D by modulation duty cycle₁(t) and D₂T the rule change of (), can The output voltage making traditional modulation is:

V_o(t)=V_o1(t)-V_o2(t)=U_m×sin(wt) (7)

The double Boost inverter of list inductance of the present invention uses the method for Time-sharing control only to make in during arbitrary half-wave of output AC electricity Having a road DC/DC boosting unit to be in HF switch state, another road is then in power frequency switching state.As it is shown on figure 3,

In the positive half period of output sinusoidal voltage (i.e. load voltage), control switching tube S1 and be in HF switch state, Controlling switching tube S2, S7 and be in normal open state, S3 Yu S1 signal complementation conducting, Boost1 unit is in pressure-increasning state, should Road output voltage is the half period half-sinusoid of a band direct current biasing；Boost2 unit is then in power frequency switching state, i.e. switching tube S4, S5, S6 are in off state, and Boost2 output voltage is then input direct voltage.Boost1 Yu Boost2 two-way is poor Dynamic output is output to the voltage loading two ends.

In the negative half-cycle of output sinusoidal voltage, control switching tube S1 still in HF switch state, control switching tube S4 Yu S6 is in normal open state, and switching tube S5 turns on S1 complementation, and Boost2 unit is in pressure-increasning state, this road output electricity Pressure is the half-sinusoid of the half period of a band direct current biasing；Boost1 is then in power frequency switching state, i.e. switching tube S2, S3, S7 Being in off state, the output voltage of Boost1 unit is then input direct voltage.Export through Boost1 Yu Boost2 two-way Differential, obtain negative half-cycle power frequency sinusoidal voltage.So during whole power frequency period, two-way boosting unit timesharing is boosted Work, at the i.e. available required pure sinusoid alternating voltage of load end differential output.The gain of this changer and single Boost It is identical.It is derived from by equation below:

$\mathrm{Vo}=\frac{1}{1-D}\×V_{\mathrm{in}}---\left(8\right)$

Wherein, Vo is the output voltage of inverter, and D is the dutycycle of Boost circuit.

Require that the unit single channel output voltage being in boosting met within the power frequency half period simultaneously:

Vo (t)=U_m×sin(wt)+V_in (9) Associating above formula can obtain:

$D\left(t\right)=\frac{U_m\×\sin \left(\mathrm{wt}\right)}{V_{\mathrm{in}}+U_m\×\sin \left(\mathrm{wt}\right)}---\left(10\right)$

So timesharing makes Boost1 boosting unit change by formula (10) with the dutycycle of Boost2 boosting unit, output voltage can be made Obtain desired sinusoidal voltage, as shown in Figure 3.

Fig. 4 is the driving signal of switching tube S1, S3, S5, and Fig. 5 is the driving signal of switching tube S2, S7, S4, S6.Fig. 6 Illustrating collection radio pressure and inductive current that switching device bears, what vertical coordinate was followed successively by switching tube S6 penetrates collecting voltage, inductance L Electric current, switching tube S1 collection radio pressure, switching tube S2 collection radio pressure.The vertical coordinate of Fig. 7 indication circuit output capacitance successively C1 both end voltage, electric capacity C2 both end voltage, input direct voltage, output AC voltage.

Claims (3)

1. the double Boost inverter of single inductance, including Boost boosting unit I, Boost boosting unit II, boost inductance, switching tube I, the input of Boost boosting unit I is connected in parallel with the input of Boost boosting unit II, the outfan of the outfan of Boost boosting unit I and Boost boosting unit II be connected in series after as the outfan of this inverter, the outfan of inverter includes the first end, the second end, and Boost boosting unit I includes switching tube II, switching tube III；Boost boosting unit II includes switching tube IV, switching tube V；Described switching tube all includes input, outfan, control end, wherein, the input of switching tube II is as the input of Boost boosting unit I, the input of switching tube III is as the outfan of Boost boosting unit I, the outfan of switching tube II is connected with the outfan of switching tube III, the input of switching tube IV is as the input of Boost boosting unit II, the input of switching tube V is as the outfan of Boost boosting unit II, the outfan of switching tube IV is connected with the outfan of switching tube V, it is characterized in that, also include switching tube VI, switching tube VII, connecting valve pipe VI between first end and the positive pole of DC source of inverter output end, connecting valve pipe VII between second end and the DC power anode of inverter output end；Boost boosting unit I and Boost boosting unit II share a boost inductance and switching tube I, wherein, the positive pole of one end DC source of boost inductance connects, and the other end of boost inductance, the input of switching tube I are all connected with positive pole, the positive pole of Boost boosting unit II input of Boost boosting unit I input.

The double Boost inverter of single inductance the most according to claim 1, it is characterised in that: equal parallel diode between the input of switching tube, outfan, the anode of diode is connected with the outfan of switching tube, and the negative electrode of diode is connected with the input of switching tube.

3. control method based on the double Boost inverter of inductance single described in claim 1, it is characterized in that: in sinusoidal wave positive half period, controlling switching tube I and be in HF switch state, switching tube II, switching tube VII are in normal open state, control switching tube III conducting complementary with switching tube I；In sinusoidal wave negative half-cycle, controlling switching tube I and be in HF switch state, switching tube IV, switching tube VI are in normal open state, control switching tube V conducting complementary with switching tube I.