CN207782666U - A kind of switching capacity two-way DC converter single supply integrated driving - Google Patents

Abstract

The utility model discloses a kind of switching capacity two-way DC converter single supply integrated drivings, the utility model dexterously combines main circuit switch pipe working condition, boostrap circuit is constituted using diode and capacitance, driving voltage is provided for each switching tube, so as to use single isolated power supply module for power supply.The driving chip of MOSFET is simple in structure and is easily integrated, and the power module being isolated includes the inverter circuit, high frequency transformer and secondary side rectification circuit of primary side, occupies the major part of driving circuit cost and volume.The utility model proposes be suitable for the high-gain two-way DC converter single supply driving circuit based on switched capacitor network, contribute to reduce driving circuit cost, improve power density.

Description

A kind of switching capacity two-way DC converter single supply integrated driving

Technical field

The utility model belongs to the application of new energy distributed power generation field energy storage converter, and in particular to a kind of switch electricity Hold two-way DC converter single supply integrated driving.

Background technology

It is rapidly developed as the new energy distributed generation technology of representative using photovoltaic, wind-powered electricity generation, fuel cell, for optimizing China Energy resource structure realizes economy, the sustainable development of environment has important strategic importance.Energy-storage system of accumulator is as a kind of energy Source buffer cell, can effectively improve regenerative resource, there are fluctuation, intermittent adverse effects to power grid transmission power. In energy storage converter, two-way DC converter is the key that undertake storage battery energy to adjust to high voltage dc bus power bi-directional Role, on the one hand, when generation of electricity by new energy amount is more than network load demand, energy extra on busbar is become through step-down type dc Parallel operation charges a battery, on the other hand, when generation of electricity by new energy amount is less than workload demand, the electricity in accumulator is boosted DC converter feeds back to power grid, realizes the effect of peak load shifting.In general, the case where considering accumulator series characteristic and safety Under, port voltage may be no more than 48V, and the voltage class of typical DC microgrid mainly has 200V, 270V, 400V and 540V It is several.Therefore, above-mentioned DC converter removes and needs to meet energy in bidirectional flow, it is also necessary to have higher voltage gain.

Traditional DC converter, acceptor's circuit parasitic parameter and controller performance influence, though duty ratio reach close to 0 or 1 limiting condition, it is also difficult to which there is higher voltage gain.Power tube is connected within the extremely short time, and bears relatively large Voltage, current stress, serious switching loss and switching noise certainly will be caused, efficiency significantly reduces.Coupling inductance and switch Capacitance network is to realize non-isolated high-gain DC transformation technical way at present.Switched capacitor network is skilful by switching Multiple capacitance charged in parallels are realized wonderfully, later discharged in series again, improve converter output voltage.Become with other high-gain DCs The technology of changing is compared, and switching capacity inductance network type has that efficient, power density is big, is easy to modular significant advantage, in It has a good application prospect in small-power type energy storage converter.

Typical switched capacitor network high-gain DC converter topology is as shown in Figure 1.Compared to Traditional DC converter, Based on the DC converter of switched capacitor network in high-gain lifting/voltage reducing occasion, contribute to the voltage stress for reducing switching device With the demand of passive element.To further increase voltage gain, it is more that multiple fundamental voltage gains expansion units compositions can be introduced Unit switch capacitance network high-gain DC converter, as shown in Figure 2.Usual 2~3 units can meet above application field Close the demand of voltage gain.Under identical voltage gain, on the one hand multiple-unit converter reduces power semiconductor device and single Capacitance voltage stress reduces input current ripple and magnetic element demand on the other hand by reduction boosting duty ratio.In addition, Multicell switch capacitance network flexible design can adjust the quantity of basic unit according to voltage gain demand.

Switched capacitor network high-gain DC converter shown in Fig. 1 introduces the switching device of multiple not common sources, therefore needs Separate power module is wanted to provide driving voltage.Typical driving circuit design is as shown in block diagram 3, when driving 3 is not total When the switching device of source electrode, 3 isolated form driving powers are needed.Especially for multiple-unit high-gain DC converter shown in Fig. 2, Driving circuit needs to provide an isolated power supply for each MOSFET.In MOSFET driving circuits, driving chip structure letter List and the driving power for being easily integrated, and being isolated include the inverter circuit, high frequency transformer and secondary side rectification circuit of primary side, significantly Increase the cost and volume of driving circuit.

Utility model content

The purpose of this utility model is to provide switching capacity two-way DC converter single supply integrated driving always, letters Change the high-gain two-way DC converter driving circuit based on switched capacitor network, realizes the inexpensive, small-sized of single supply power supply Change modular event driven design.

To achieve the goals above, the utility model is achieved using following technical scheme：

A kind of switching capacity two-way DC converter single supply integrated driving, including inverter main circuit and driving circuit,

Include N number of power tube S in inverter main circuit_jWith N-1 DC capacitor C_k, 1≤j≤N, 1≤k≤N-1, wherein N The source electrode and drain electrode of a power tube, which is sequentially connected, connects composition cascaded structure, and adjacent arbitrary power tube working condition is complementary；It is any Capacitance C_kIt is connected in parallel on upper tube S in two concatenated power tubes respectively_k+1Source electrode and down tube S_kDrain electrode both ends, 1≤k≤N-1；

Driving circuit includes N number of driving chip, a DC-DC isolated power supplies module, N number of electric capacity of voltage regulation C_PiWith N-1 two Pole pipe D_i, 1≤i≤N；The gate pole output end v of wherein each driving chip_giRespectively through the resistance R that overdrives_gMeet power tube S_iDoor Pole, the negative terminal v of driving chip gate drive voltage_siMeet power tube S_iSource electrode, DC voltage-stabilizing capacitance C_PiConnect driving chip outlet side Positive and negative both ends v_diAnd v_siBetween；Diode D_jMeet the two driving chip driving voltage anode v closed on_djAnd v_d(j+1)Between.

Diode D as a further improvement of the utility model,₂、D₃…D_NVoltage stress be respectively capacitance C₁、C₂… C_N-1。

The gate capacitance value of bootstrap capacitor meets as a further improvement of the utility model,：

Wherein：Q_gFor power tube gate charge, V_CpkTo drive capacitance voltage, ε_maxFor preset maximum capacitor voltage Drop coefficient.

Compared with prior art, the utility model has the advantages that：

The utility model two-way DC converter single supply driving circuit dexterously combines main circuit power tube work shape State constitutes boostrap circuit using diode and capacitance, driving voltage is provided for each power tube, so as to using single isolation electricity Source module is powered.MOSFET driving chips are simple in structure and are easily integrated, and the power module being isolated includes the inversion electricity of primary side Road, high frequency transformer and secondary side rectification circuit occupy the major part of driving circuit cost and volume.The utility model is by drawing Enter diode-condenser network network, in conjunction with the conducting channel design driven circuit of MOSFET, realizes the list to multiple MOSFET Power supply power supply；The utility model proposes a kind of high-gain two-way DC converter list electricity being suitable for based on switched capacitor network Source driving circuit helps to reduce driving circuit cost, improves power density.

When converter works normally, two power tube complementations of arbitrary neighborhood are connected the control method of the utility model, Under two kinds of operating modes of driving circuit, the output capacitance Cp of isolated power supply₁It dexterously sequentially completes to high-pressure side MOFET Driving chip exports the power supply of lateral capacitance, realizes the single supply power supply of more MOSFET cascaded structures.

Description of the drawings

Fig. 1 a are a kind of high-gain two-way DC converter main circuit based on switched capacitor network；

Fig. 1 b are a kind of high-gain two-way DC converter main circuit based on switched capacitor network；

Fig. 1 c are a kind of high-gain two-way DC converter main circuit based on switched capacitor network；

Fig. 2 a are a kind of multicell switch capacitance network high-gain two-way DC converter main circuit；

Fig. 2 b are a kind of multicell switch capacitance network high-gain two-way DC converter main circuit；

Fig. 2 c are a kind of multicell switch capacitance network high-gain two-way DC converter main circuit；

Fig. 3 is existing switched capacitor network high-gain DC converter driving circuit structure schematic diagram (3 power tubes)；

Fig. 4 a are the utility model single supply driving circuit structure schematic diagram (3 switches)；

Fig. 4 b are the utility model single supply driving circuit structure schematic diagram (N number of switch)；

Fig. 5 a are the driving circuit simulation waveform one that Fig. 1 c converters use single supply drive scheme；

Fig. 5 b are the driving circuit simulation waveform two that Fig. 1 c converters use single supply drive scheme；

Fig. 5 c are the driving circuit simulation waveform three that Fig. 1 c converters use single supply drive scheme；

Fig. 5 d are the driving circuit simulation waveform four that Fig. 1 c converters use single supply drive scheme；

Fig. 5 e are the driving circuit simulation waveform five that Fig. 1 c converters use single supply drive scheme；

Fig. 5 f are the driving circuit simulation waveform six that Fig. 1 c converters use single supply drive scheme；

Fig. 6 a are the main circuit simulation waveform one that Fig. 1 c converters use single supply drive scheme；

Fig. 6 b are the main circuit simulation waveform two that Fig. 1 c converters use single supply drive scheme；

Fig. 6 c are the main circuit simulation waveform three that Fig. 1 c converters use single supply drive scheme；

Fig. 6 d are the main circuit simulation waveform four that Fig. 1 c converters use single supply drive scheme；

Fig. 7 a are the experimental waveform a power tube driving voltage waveforms that Fig. 1 c converters use single supply drive scheme, b master Circuit inductance electric current, output voltage, power tube voltage and current oscillogram one；

Fig. 7 b are the experimental waveform a power tube driving voltage waveforms that Fig. 1 c converters use single supply drive scheme, b master Circuit inductance electric current, output voltage, power tube voltage and current oscillogram two.

Specific implementation mode

The utility model is described in more detail below in conjunction with the accompanying drawings.

The key idea of the utility model is to utilize diode and capacity cell, in conjunction with main circuit switch device operating mode Design driven circuit dexterously gives the capacitance of driving power to provide charge circuit, and then reduces the demand of isolation drive power supply.

As shown in figures 4 a and 4b, a kind of high-gain two-way DC converter single supply driving based on switched capacitor network Circuit, including inverter main circuit and driving circuit include N number of MOSFET power tubes S in inverter main circuit_j(1≤j≤N) With N-1 DC capacitor C_k(1≤k≤N-1), wherein N number of MOSFET power tubes source electrode and drain electrode, which is linked in sequence, constitutes tandem junction Structure, adjacent arbitrary power tube (MOSFET) working condition are complementary；Any capacitance C_kIt is connected in parallel on respectively in two Series power pipes Upper tube S_k+1Source electrode and down tube S_kDrain electrode both ends (1≤k≤N-1).This patent utility model is by introducing diode-capacitance Circuit network is realized and is powered to the single supply of multiple power tubes in conjunction with the conducting channel design driven circuit of power tube；

Specific single supply driving circuit main feature is as follows：

Driving circuit includes N number of driving chip, a DC-DC isolated power supply module, N number of electric capacity of voltage regulation C_Pi(1≤i≤N) With N-1 diode D_i(1≤i≤N)；The gate pole output end v of wherein each driving chip_giRespectively through the resistance R that overdrives_gConnect power Pipe S_iGate pole (1≤i≤N), the negative terminal v of driving chip gate drive voltage_siMeet power tube S_iSource electrode (1≤i≤N), direct current is steady Voltage capacitance C_PiMeet the positive and negative both ends v of driving chip outlet side_diAnd v_siBetween (1≤i≤N), provide driving voltage for it；Two poles Pipe D_jTo meet close on two driving chip driving voltage anode v_djAnd v_d(j+1)Between；

When converter works normally, two MOSFET complementations conducting of arbitrary neighborhood, including two kinds of operating modes, pattern 1： PWM=1,At this point, S₁、S₃、S₅…S_j(j is odd number) open-minded, S₂、S₄、 S₆…S_k(k is even number) turns off and pattern 2：PWM=1,At this point, S₁、S₃、S₅…S_j(j is odd number) turns off, S₂、S₄、S₆…S_k(k is even number) is open-minded.Work as S₁It opens When logical, C_P1Through resistance R_gTo S₁Gate pole charges, and through diode D₂And S₁To for MOSFET driving chip #2 electric capacity of voltage regulation C_P2For Electricity, at this time S₂Shutdown, diode D₃Bear back-pressure cut-off, S₃It is open-minded, electric capacity of voltage regulation C_P3Through R_gTo S₃Gate pole is powered, and through two poles Pipe D₄And S₃To for driving chip #4 electric capacity of voltage regulation C_P4Charging, and so on.Work as S₁When shutdown, D₂Bear back-pressure cut-off, S₂It opens It is logical, electric capacity of voltage regulation C_P2Through resistance R_gTo S₂Gate pole charges, and through diode D₃And S₂To for driving chip #3 electric capacity of voltage regulation C_P3For Electricity, S₃Shutdown, diode D₂Back-pressure cut-off is born, and so on.Under two kinds of operating modes of driving circuit, isolated power supply Output capacitance C_p1D₂The power supply for exporting lateral capacitance to high-pressure side MOFET driving chips is dexterously sequentially completed, is realized more The single supply of MOSFET cascaded structures is powered.

Diode D₂、D₃…D_NVoltage stress be respectively capacitance C₁、C₂…C_N-1。

Bootstrap capacitor should provide enough gate charges and ensure that MOSFET is quickly open-minded, and enough gate poles is maintained to open electricity Pressure.Gate capacitance value meets：

Wherein：Q_gFor MOSFET gate charges, V_CpkTo drive capacitance voltage, ε_maxFor preset maximum capacitor voltage Drop coefficient.

In conjunction with shown in 4a and Fig. 4 b, the utility model additionally provides the control method of the circuit, is as follows：

It is assumed that capacitance voltage of respectively booting in initial time driving circuit is zero.When input pwm signal is 1 (PWM=of logic 1) when, all even number power tube shutdowns.The #1 outputs of MOSFET driving chips are provided with reference to high level by isolated power supply, therefore S₁It is suitable Profit conducting.Remaining odd number power tube due on corresponding bootstrap capacitor voltage be zero and can not open.S₁Conducting is so that this moment S₂ Source potential and S₁Source potential it is equal, i.e. capacitance C_P2Negative polarity end and DC voltage-stabilizing capacitance C_P1The electricity such as negative polarity end Gesture, therefore diode D₂Forward bias is connected, DC voltage-stabilizing capacitance C_P1To DC voltage-stabilizing capacitance C_P2Charge to C rapidly_P2Both ends electricity Pressure is isolated power supply output voltage, is subsequent time S₂Open and prepare.

Later, when it is logical zero (PWM=0) to input pwm signal, all odd number power tube shutdowns.Due in the PWM=1 phases Between, C_P2From C_P1It obtains energy storage and simultaneously keeps certain voltage, therefore when driving chip #2 outputs are with reference to high level can smoothly open S₂。 Remaining even number power tube cannot achieve conducting due to no-voltage on corresponding bootstrap capacitor.Similar, S₂When conducting makes this Carve S₃Source potential and S₂It is equal, i.e. capacitance C_P3Negative polarity end and C_P2Negative polarity end equipotential, therefore D₃Forward bias Conducting, C_P2To C_P3It is equal to charge to two capacitance voltages, is subsequent time S₃Offer high level cut-in voltage.Repeat above-mentioned step Suddenly, when the circuit reaches steady state, the voltage of approximate isolated power supply output, thus each power can be obtained on each bootstrap capacitor Smoothly being switched on and off for MOSFET can be protected.

When stable state, the voltage of all bootstrap capacitors is approximately the voltage of isolated power supply module.In power stage circuit, Suo Youqi Number power tube (S₁、S₃...) source potential immobilize, be main circuit in corresponding capacitance voltage；All even number power tube (S₂、 S₄...) source potential be float, with circuit operating pattern period switch and change.As PWM=1, all odd number work( Rate pipe is both turned on, all even number power tube S_kSource potential be equal to its adjacent low level odd number power tube S_k-1Source potential, very The bootstrap capacitor C of numerical digit_P(k-1)To the bootstrap capacitor C of an adjacent high position_P(k)Charging.As PWM=0, all even number power tubes are led It is logical, all even number power tube S_kSource potential be equal to its adjacent high-order odd number power tube S_k+1Source potential, even bit bootstrapping Capacitance C_P(k)To the bootstrap capacitor C of an adjacent high position_P(k+1)Charging.

Bootstrap capacitor should provide sufficiently large gate charge Q_gEnsure that MOSFET is quickly open-minded, and maintains sufficiently high gate pole Voltage ensures that MOSFET power tubes are in the conduction state.According to drive circuit works principle, in the mistake for opening MOSFET power tubes Cheng Zhong, corresponding capacitance is through driving resistance to charge to gate pole, and capacitance voltage is from V_{c_max}Decline V_{c_min}, when MOSFET power tubes are connected When, gate current very little, capacitance voltage maintains approximately constant.After MOSFET power tubes turn off, by power supply and previous stage capacitance It charges to capacitance present.

To keep driving chip high-level output voltage reliable and stable in actual circuit, pressure drop Δ V should be reduced as far as possible.Definition Voltage Drop coefficient ε is the ratio that Δ V and capacitance steady state voltage drop in capacitance voltage.

Capacitance pressure drop Δ V meets with MOSFET gate charges Qg：

Q_g=C Δs V (3)

Combine (2) and (3), capacitance value meets：

Wherein：ε_maxFor preset maximum capacitor Voltage Drop coefficient.

To verify above-mentioned novel single supply driving circuit and theory analysis, the utility model gives a design example.

As shown in fig. 4 a, as illustrated in figure 1 c, parameter is as follows for main circuit for driving circuit：v_in=50V, P_o=500W, v_o= 400V,f_s=100kHz, v_CP1=12V, L=100uH, L_f=1mH, C₁=C₂=50uF, C_o=50uF, R_L=320 Ω.

Fig. 5 a- Fig. 5 f, provide using the utility model proposes single supply driving circuit, each MOSFET driving electricity Press v_Gs1,v_Gs2,v_Gs3, diode voltage v_D2,v_D3,v_Gs3With capacitance voltage v_CP2, it is multiple MOSFET to effectively realize single supply Power device provides stable driving voltage and ensures that it is reliably turned on and off.

Fig. 6 a- Fig. 6 d, provide using the utility model single supply driving circuit, main circuit inductive current, switch mosfet Voltage, electric current and output voltage waveforms.

Fig. 7 a- scheme b, provide Fig. 1 c main circuits v_in=48V, v_o=200V, f_s=100kHz, v_CP1=12V, L=1mH, L_f =5mH, C₁=C₂=50uF, C_o=50uF, R_LExperimental waveform under=100 Ω operating modes.Emulation and experimental result and theory analysis It is almost the same.

Isolated power supply occupies the major part of power device driving plate cost and volume.It is suitable that the utility model discloses one kind Single supply driving circuit design method for switched capacitor network high-gain DC converter effectively simplifies driving circuit The demand of design and isolated power supply in the case that especially switching device is more in main circuit, helps to reduce driving plate device Cost improves power density.

Finally, it should be noted that above-described embodiment is only to illustrate the technical solution of the utility model, and not to reality Apply the restriction of mode.For those of ordinary skill in the art, before not departing from the utility model thought and range It puts, can carry out other various forms of changes and improvements on the basis of the above description, these changes and improvements should be still in Among the protection domain that the utility model is created.The utility model requires protection scope is by appended claims and its equivalent Object defines.

Claims (3)

1. a kind of switching capacity two-way DC converter single supply integrated driving, which is characterized in that including inverter main circuit and Driving circuit,

Include N number of power tube S in inverter main circuit_jWith N-1 DC capacitor C_k, 1≤j≤N, 1≤k≤N-1, wherein N number of work( The source electrode and drain electrode of rate pipe, which is sequentially connected, connects composition cascaded structure, and adjacent arbitrary power tube working condition is complementary；Any capacitance C_kIt is connected in parallel on upper tube S in two concatenated power tubes respectively_k+1Source electrode and down tube S_kDrain electrode both ends, 1≤k≤N-1；

Driving circuit includes N number of driving chip, a DC-DC isolated power supplies module, N number of electric capacity of voltage regulation C_PiWith N-1 diode D_i, 1≤i≤N；The gate pole output end v of wherein each driving chip_giRespectively through the resistance R that overdrives_gMeet power tube S_iGate pole drives The negative terminal v of dynamic chip gate drive voltage_siMeet power tube S_iSource electrode, DC voltage-stabilizing capacitance C_PiIt is positive and negative to connect driving chip outlet side Both ends v_diAnd v_siBetween；Diode D_jMeet the two driving chip driving voltage anode v closed on_djAnd v_d(j+1)Between.

2. switching capacity two-way DC converter single supply integrated driving according to claim 1, which is characterized in that two poles Pipe D₂、D₃…D_NVoltage stress be respectively capacitance C₁、C₂…C_N-1。

3. switching capacity two-way DC converter single supply integrated driving according to claim 1, which is characterized in that bootstrapping The gate capacitance value of capacitance meets：

Wherein：Q_gFor power tube gate charge, V_CpkTo drive capacitance voltage, ε_maxFor preset maximum capacitor Voltage Drop Coefficient.