WO2019029250A1 - 一种电源系统 - Google Patents

一种电源系统 Download PDF

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Publication number
WO2019029250A1
WO2019029250A1 PCT/CN2018/090365 CN2018090365W WO2019029250A1 WO 2019029250 A1 WO2019029250 A1 WO 2019029250A1 CN 2018090365 W CN2018090365 W CN 2018090365W WO 2019029250 A1 WO2019029250 A1 WO 2019029250A1
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Prior art keywords
power conversion
module
output
conversion module
input
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PCT/CN2018/090365
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English (en)
French (fr)
Inventor
郭启利
王志燊
刘湘
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广州金升阳科技有限公司
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Publication of WO2019029250A1 publication Critical patent/WO2019029250A1/zh

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    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
    • H02M3/00—Conversion of dc power input into dc power output
    • H02M3/22—Conversion of dc power input into dc power output with intermediate conversion into ac
    • H02M3/24—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters
    • H02M3/28—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac
    • H02M3/325—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal
    • H02M3/335—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal using semiconductor devices only
    • H02M3/33507—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal using semiconductor devices only with automatic control of the output voltage or current, e.g. flyback converters
    • H02M3/33523—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal using semiconductor devices only with automatic control of the output voltage or current, e.g. flyback converters with galvanic isolation between input and output of both the power stage and the feedback loop
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
    • H02M1/00—Details of apparatus for conversion
    • H02M1/0067—Converter structures employing plural converter units, other than for parallel operation of the units on a single load
    • H02M1/0074—Plural converter units whose inputs are connected in series
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
    • H02M1/00—Details of apparatus for conversion
    • H02M1/0083—Converters characterised by their input or output configuration

Definitions

  • the present invention relates to a power supply system, and more particularly to applications for high voltage input, modular applications.
  • high-voltage input occasions such as photovoltaic power supply
  • the high voltage can reach 1500V or higher. Therefore, it is necessary to increase the rated voltage of the switch of the latter-stage converter.
  • the on-state resistance of the high-voltage MOSFET is large, resulting in large conduction loss and high cost.
  • the most basic method for building a power system with a standard power module is to use a series-parallel combination of input/output. Taking two identical power modules as an example, the following four power systems can be combined by using the input/output series-parallel method:
  • System 1 Input parallel, output parallel system
  • System 2 input series, output parallel system
  • System 3 input parallel, output series system
  • System 4 Input series, output system in series.
  • the first system has been widely used.
  • Typical products include high-power communication power systems, high-power UPS systems, etc.
  • the other three systems are not widely used.
  • Each module in system 2 is preferably independent of each other, that is, each has its own control and power supply.
  • each module cannot be made into a precise voltage regulation of the output voltage as a single standard power supply, because in that case, the current of each module connected in parallel at the output terminal will cause a very large unevenness due to the factory setting value error of the module voltage. This will also cause the modules to be extremely uneven in their input voltage, which will affect the reliability and even damage of the module. Therefore, it is generally impossible to directly connect the input and the output to the power supply module with precision voltage regulation.
  • the input impedance of the small signal model of the Royer circuit is positive, which is more suitable for series-parallel systems.
  • the Royer circuit is used in the high-voltage system. The selection of the switching tube is difficult, and it is not suitable for the series-parallel system under high voltage. in.
  • the switching power supply has attracted much attention for its volume and flexibility.
  • high-power ultra-thin products the volume of high-voltage devices and the size of the transformer seriously affect the overall product height.
  • One is to use the series-parallel form of the transformer to spread the power in several transformers, reduce the volume of the transformer, thereby reducing the volume of the entire switching power supply; another way is to connect the modules in series and parallel. Power expansion through series and parallel connection of several small power modules.
  • the current parallel connection structure of two modules is required to add an additional current sharing circuit outside the module.
  • the external control of the application is complicated, and there are certain professional restrictions for the customer. Some non-electronic professional Ordinary customers cannot simply implement. Or through some topologies with positive impedance characteristics, the primary side series side parallel is used for its unique natural voltage equalization.
  • FIG. 1 is a schematic diagram of two modules directly inputting serial output in parallel
  • FIG. 2 is a direct input of two modules in parallel and serial output.
  • FIG. 3 is a schematic diagram of a parallel connection structure of a plurality of modules directly inputting a series output
  • FIG. 4 is a schematic structural diagram of a plurality of modules directly inputting a series output parallel and adding a voltage stabilizing module.
  • the first embodiment of the utility model patent No. 201621402396.3 adopts two 60W standard power conversion modules with an input voltage range of 120 VDC to 240 VDC as a 120 W power supply system in series and parallel, and the input connection thereof under open loop control.
  • the output parallel effect was verified experimentally.
  • the accuracy of the input voltage accuracy of the module will decrease.
  • the two extreme deviations of the control parameters can be further deviated from the two extremes of the power level parameters, and then combined according to the size of the module gain.
  • the two modules A and B with the largest gain and the smallest gain correspond to the following parameters:
  • the module with the largest gain L m(min) , L r(min) , C r(min) , D mac , f s(min) ;
  • the module with the smallest gain L m(max) , L r(max) , C r(max) , D min , f s(max) .
  • Combination 1 Input series/output parallel experiment with power level and control as nominal parameters
  • Combination 2 Input series/output parallel experiment with power stage and duty cycle as nominal parameters, but switching frequency is upper and lower deviation respectively
  • Combination 3 Input series/output parallel experiment with power stage and switching frequency as nominal parameters, but the duty ratio is upper and lower deviation respectively
  • Combination 4 The switching frequency and duty cycle are nominal parameters, but the power level parameters are the input series/output parallel experiment of the upper and lower deviations respectively.
  • Combination 5 Input series/output parallel experiment with duty cycle as nominal parameter, but power level parameter and switching frequency are upper and lower deviation respectively
  • Table 1 The experimental data of the input voltage equalization effect and the output current sharing effect of the system are shown in Table 1 and Table 2.
  • the combination 1 is the data with good consistency between the two modules. It can be seen from the data that the consistency is guaranteed.
  • the input equalization accuracy is less than 1%, and the current sharing accuracy is also within ⁇ 1%. Even if the inconsistency of the two modules is considered, the equalization and current sharing accuracy are within ⁇ 10% accuracy.
  • Table 3 shows the output voltage values of various parameter combinations for different input voltages and full output.
  • Vg 300V ⁇ 0.67% ⁇ 1.23% ⁇ 8.7% ⁇ 6.8% ⁇ 5.6%
  • Vg 400V ⁇ 0.38% ⁇ 1.20% ⁇ 8.2% ⁇ 6.8% ⁇ 5.5%
  • Vg 530V ⁇ 0.15% ⁇ 1.21% ⁇ 8.0% ⁇ 6.9% ⁇ 5.6%
  • Table 2 Full-load output current sharing accuracy of various parameter combinations under different input voltages
  • the duty ratio of the main control IC can be changed by detecting its own input voltage.
  • the output voltage of the individual modules is stable, and the pre-regulation of the module is realized.
  • the simplest input feedforward is to make the duty cycle of each module inversely proportional to its own input voltage. Let's analyze the effect of adding a feedforward unit on the impedance characteristics of the module.
  • the duty cycle of the module decreases, and the decrease of the duty cycle causes the output power of the module to decrease, thereby causing the
  • the reduction of the input power of the module finally causes the voltage across the input capacitor of the module, that is, the input voltage of the module continues to rise, forming a positive feedback. If the loop continues, the input voltage of the module will become higher and higher, eventually resulting in two The module input voltage is extremely uneven, and it is difficult to achieve the required input voltage equalization accuracy.
  • the self-feedforward control can reduce the range of the output voltage, but the equalization accuracy of the input voltage of each module and the current sharing accuracy of the output current cannot be realized. It can be clearly seen from Fig. 5.
  • the single module is self-feedforward and cannot meet the input equalization and output current sharing accuracy of the module input series output parallel system.
  • the same use of the output voltage closed-loop duty cycle adjustment will also change the input impedance characteristics of the module, and can not meet the input equalization and output current sharing accuracy of the input series output parallel system.
  • the technical problem to be solved by the invention is: a power supply system, which realizes input voltage equalization and output current sharing requirements in an input series connection and output parallel power supply system, and can realize that the output voltage is basically stable and does not change with input changes, thereby realizing
  • the direct series-parallel connection of multiple modules makes the power system more flexible and more efficient than the two-stage solution.
  • the input stage uses multiple modules in series, so the voltage stress of each module is greatly reduced.
  • a power supply system includes N power conversion modules, N is a natural number greater than 1, and the N power conversion modules are open-loop controlled asymmetric half-bridge flyback converters, and the connection relationship is: first power The positive input end of the conversion module is the positive input end of the system, the negative input end of the first power conversion module is connected to the positive input end of the second power conversion module, and the negative input end of the second power conversion module and the third power conversion module The positive input terminal is connected, and so on, the negative input terminal of the N-1 power conversion module is connected to the positive input terminal of the Nth power conversion module, and the negative input terminal of the Nth power conversion module is used as the negative input terminal of the system; The positive output ends of the N power conversion modules are connected as the positive output end of the system, and the negative output ends of the N power conversion modules are connected as the negative output ends of the system; the first power conversion module and the first power conversion module The two power conversion modules perform cross feedforward control, the second power conversion mode and the third power conversion mode perform cross feedforward control, and so on,
  • the asymmetric half-bridge flyback converter comprises: a positive input terminal, a negative input terminal, a positive output terminal, a negative output terminal, a first filter capacitor, a first switch transistor, a second switch transistor, a control circuit, a resonance capacitor,
  • the power device, the output rectifier diode, and the second filter capacitor includes: a leakage inductance of the transformer and the transformer, and a magnetizing inductance of the transformer;
  • the first filter capacitor is connected between the positive input terminal and the negative input terminal, and the first switch transistor is The conduction current outflow end is connected to the conduction current inflow end of the second switch tube, the conduction current inflow end of the first switch tube is connected to the positive input end, and the conduction current outflow end of the second switch tube is connected to the negative input end,
  • One end of the resonant capacitor is connected to the conduction current outflow end of the first switch tube, and the other end is connected to the same name end of the primary side of the transformer.
  • the different name end of the primary side of the transformer is connected to the negative input end, and the different name end and output of the secondary side of the transformer are connected.
  • the anode of the rectifier diode is connected, one end of the second filter capacitor is connected to the cathode of the output rectifier diode as a positive output terminal, and the other end of the second filter capacitor is connected to the transformer pair
  • the control circuit includes a PWM generating circuit, a driving circuit, and an isolated sampling circuit, the isolating sampling circuit is used for sampling the input voltage in equal proportion, and the driving circuit is connected to the control end of the first switching tube and the second switching tube
  • the PWM generating circuit outputs a PWM signal to the driving circuit for controlling the first switching tube and the second switching tube.
  • the first switch tube and the second switch tube are MOS tubes or triode tubes.
  • the driving pulse signals of the first switching transistor and the second switching transistor are staggered to prevent a dead time of the common short circuit.
  • the dead time is 300 nS.
  • Cross feedforward control The feedforward signal of other power modules is used to control the duty cycle of the power supply.
  • the input series output of two power modules is connected in parallel, and the feedforward signal of the first power module is connected to the second power module.
  • the duty ratio control circuit controls the duty ratio of the first power module, and the feedforward signal of the second power module is connected to the duty cycle control circuit of the first power module to control the duty ratio of the second power module.
  • the control terminal of the switch tube the port that controls the conduction switch to be turned on and off.
  • the MOS transistor it refers to the gate of the MOS transistor; for the triode, it refers to the base of the triode.
  • the on-current of the switching transistor flows in: the port through which the current flows after the switching transistor is turned on, such as the MOSFET, refers to the drain of the MOS transistor, regardless of the N-channel, P-channel, enhanced or depleted MOS When the tube is turned on, the current flows from the drain with a high voltage to the source with a low voltage.
  • the triode it refers to the collector of the triode. When turned on, the current flows from the collector with a high voltage to a low voltage. The emitter.
  • the conduction current flowing out of the switch tube After the switch tube is turned on, the current flowing out of the port, for the MOS tube, refers to the source of the MOS tube; for the triode, the emitter of the triode.
  • Feedforward signal A signal obtained by detecting the input voltage of the power module itself.
  • the present invention has the following beneficial effects:
  • the input series output parallel system has a small output voltage floating range
  • the present invention adopts modular thinking and splits the system into N identical standard modules
  • the user can directly use the standard module to set up the system freely according to the requirements.
  • the use is flexible and the portability is high.
  • the system has low requirements for the customer.
  • the input of the module can be directly connected and the output can be connected in parallel. Professional knowledge;
  • each standard module uses DC voltage signal, multi-module input series, output parallel system is easy to lay, no mutual interference.
  • Figure 1 is a block diagram of a utility model patent dual module input series output parallel system with application number 201621402396.3;
  • Figure 2 is a block diagram of a dual-module input series output parallel system with a voltage regulator module with a utility model patent of 201621402396.3;
  • Figure 3 is a block diagram of an input series output parallel system of N standard modules of utility model patent of 201621402396.3;
  • Figure 4 is a block diagram of an input series output parallel system of N standard modules with a voltage regulator module of the utility model patent of 201621402396.3;
  • Fig. 5 is a schematic diagram showing the theoretical analysis process of the primary side series secondary parallel system of the self-feedback mode
  • Figure 6 is a schematic diagram of the theoretical analysis process of the primary side series secondary parallel system of the cross feedback mode
  • Figure 7 is a schematic diagram of a single module circuit of the present invention.
  • Figure 8 is a block diagram of a dual module input series output parallel system of the present invention.
  • FIG. 9 is a block diagram of an input series output parallel system of N standard modules of the present invention.
  • Figure 10 is a schematic block diagram of the circuit of the first embodiment
  • Figure 11 is a schematic circuit diagram of the second embodiment.
  • the inventor of the present application has developed a new concept of feedforward control by studying the feedforward control mode of the asymmetric half-bridge flyback converter, that is, the "cross feedforward control" defined above, through each
  • the positive impedance characteristic of the symmetric half-bridge flyback converter controls the input equalization of each power conversion module in the power supply system, thereby achieving the output current sharing of the power supply system.
  • the input cross feedforward control not only has the effect of feedforward control on the input voltage. It can also automatically correct the imbalance of the input voltage of the module. The following is a brief description of this correction process:
  • a module there are two modules, A module and B module. If the input voltage of the A module becomes high for some reason, the input voltage of the B module will become lower synchronously.
  • the A module with a high input voltage is controlled by the isolation of its input voltage to control the duty cycle of the B module to reduce its duty cycle.
  • the B module with a low input voltage passes its input voltage.
  • the duty cycle of the A module is controlled to increase its duty cycle.
  • the A module with a high input voltage increases the input power due to the duty ratio, resulting in a voltage across the input capacitor, that is, a drop in the input voltage of the module (A module); the input voltage becomes lower.
  • the B module is reduced in duty cycle, resulting in a decrease in input power, resulting in a voltage across its input capacitor, which is an increase in the input voltage of the module; thus, the input voltages of both modules will be reversed from the original one.
  • the change of direction that is, the module with increased input voltage, reduces the input voltage through cross feedforward control; the module with reduced input voltage increases the input voltage through cross feedforward control. Therefore, the input cross feedforward control has the function of automatically correcting the input voltage of the module to balance.
  • FIG. 7 is a schematic diagram of a single module circuit of the present invention, using an asymmetric half-bridge flyback converter: comprising two input terminals (Vg1, input ground), two output terminals (Vo, output ground), first filtering Capacitor Cin1, first switch S11, second switch S21, control circuit 102, resonant capacitor Cr1, power device 101 (including transformer T1, leakage inductance Lr1 of transformer T1 and magnetizing inductance Lm1), output rectifier diode D1, second a filter capacitor C1, the first filter capacitor Cin1 is connected between the two input terminals, and the on current outflow end of the first switch transistor S11 is connected to the on current inflow end of the second switch transistor S21, and then first The on current inflow end of the switch S11 is connected to the input terminal Vg1, the on current out end of the second switch S21 is connected to the output ground of the output terminal, and one end of the resonant capacitor Cr1 is connected to the on current of the first switch S11.
  • the other end is connected to the same name end of the transformer T1.
  • the opposite end of the transformer T1 is connected to the output ground of the output terminal.
  • the different name of the secondary side of the transformer T1 is connected to the anode of the output rectifier diode D1.
  • the second filter capacitor C1 one of Connected to the cathode of the output rectifier diode D1 as the output terminal Vo, the other end of the second filter capacitor C1 is connected to the same-name terminal of the secondary side of the transformer T1, as the output ground of the output terminal, the control circuit 102 includes the PWM generation circuit, the drive circuit, and the isolation.
  • the sampling circuit is configured to control the first switch tube S11 and the second switch tube S21, and the isolation sampling circuit is used to sample the input voltage in equal proportion.
  • FIG. 8 is a block diagram of a dual module input series output parallel system of the present invention
  • FIG. 9 is a block diagram of an input series output parallel system of N standard modules of the present invention.
  • each module number and component code in the figure are coded according to certain rules.
  • the first number represents the component code
  • the second number represents the module number, such as the switch tube S11
  • the first one represents the S1 switch tube.
  • the second one is represented as the S1 switch in the first module
  • the switch S12 is the first switch in the second module
  • the switch S21 is the first module In the S2 switch tube
  • the switch tube S22 represents the S2 switch tube in the second module.
  • the second digit in which the module number is indicated may be omitted in some cases, and only the first digit as the component code is reserved. Specific embodiments of the invention are described in detail below.
  • FIG. 10 it is a circuit block diagram of the first embodiment.
  • the two module circuits shown in FIG. 7 are composed of a series control in a cross-control manner, including: an input terminal Vg+, an input ground Vg-, and an output terminal Vo+. Output ground Vo-; input capacitors Cin1, Cin2; upper module control circuit 102, upper module asymmetric half-bridge flyback main power circuit 100; lower module control circuit 202, lower module asymmetric half-bridge flyback main power circuit 200.
  • the upper and lower module control circuits all include an isolation sampling circuit, a PWM generating circuit, and a driving circuit.
  • the asymmetric half-bridge flyback main power circuit of the upper and lower modules comprises two module MOS tubes S11, S21, S12, S22, DC blocking capacitors Cr1, Cr2, transformers 101, 201, output loop diodes D1, D2, and output capacitor C1. , C2.
  • the connection relationship is as follows: the input terminal Vg+ is connected to the input ground Vg- through the two input capacitors Cin1 and Cin2, and the input capacitor Cin1 is respectively connected to the drain of the MOS transistor S11 of the upper module and the source of the MOS transistor S21, and input.
  • the capacitor Cin2 is connected to the drain of the MOS transistor S12 of the lower module and the source of the MOS transistor S22, respectively, and the source of the MOS transistor S21 of the upper module is connected to the drain of the MOS transistor S12 of the lower module.
  • the above module is taken as an example.
  • connection mode of the lower module is the same as that of the upper module: the source of the MOS transistor S11 of the upper module is connected to the one end 1 of the primary side of the transformer T1 through the DC blocking capacitor Cr1 (through the leakage inductance Lr1 of the transformer T1, the excitation inductance Lm1
  • the other end 2 of the primary side of the transformer T1 is connected to the source of the MOS transistor S21 of the upper module, and the one end 4 of the secondary side of the transformer T1 is connected to the anode of the output loop diode D1, and the cathode of the output loop diode D1 and the output of the power supply system
  • the positive output of Vo+ is connected, and the other end 3 of the secondary side of transformer T1 is connected to the output of the power system Vo-.
  • the cathode of the output loop diode D2 of the lower module is connected to the positive output terminal of the power supply system output terminal Vo+, and the other end 3 of the secondary side of the transformer T2 is connected to the power system output terminal Vo-.
  • C1 and C2 are connected in parallel between the output terminals Vo+ and Vo-.
  • the open loop control circuit of each module is connected to the driving circuit, and the driving circuit is respectively connected with the upper and lower MOS tubes in the module.
  • the whole system is composed of a series input and a parallel output of two upper and lower power conversion modules, and the main power stage working principle of the single power conversion module is the same as the asymmetric half bridge flyback circuit, which is known to those skilled in the art. It is a well-known technology and will not be developed here.
  • the control process is as follows: the input voltage of the upper module in the input series and output parallel system is isolated by linear buck, and the isolated voltage signal is used as the duty cycle feedforward control signal of the lower module. Similarly, the input voltage of the lower module in the series-connected, output-parallel system is isolated by linear buck isolation, and the isolated voltage signal is used as the duty cycle feedforward control signal of the lower module.
  • the input cross feedforward not only has the effect of feedforward control, but also automatically corrects the imbalance of the input voltage of the module.
  • two standard power conversion modules with input voltage range of 120 VDC to 240 VDC are used as a 120 W power supply system in order to fully verify the input equalization accuracy and output current sharing accuracy under the tolerance of the cross feedforward.
  • the impact of the test was verified by tolerance experiments.
  • the two extreme deviations of the control parameters and the two extreme deviations of the power level parameters are combined into a new two extreme deviation modules according to the power conversion module gain.
  • the two modules with the largest gain and the smallest gain correspond to the following parameters:
  • excitation inductance minimum excitation inductance minimum
  • leakage inductance minimum resonance capacitance minimum
  • frequency minimum namely: L m(min) , L r(min) , C r(min) , f s(min) ;
  • the module with the smallest gain the maximum value of the magnetizing inductance, the maximum leakage inductance, the maximum value of the resonant capacitor, and the maximum frequency, namely: L m(max) , L r(max) , C r(max) , f s(max) .
  • Combination 1 Input series/output parallel experiment with power level and control as nominal parameters
  • Combination 2 Input series/output parallel experiment with power level as nominal parameter but switching frequency is up and down deviation
  • Combination 3 The switching frequency is the nominal parameter, but the power level parameters are the input series/output parallel experiment of the upper and lower deviations respectively.
  • Combination 4 Input series/output parallel experiment with power level parameters and switching frequency being upper and lower deviations respectively
  • the experimental data of the input voltage equalization effect and the output current sharing effect of the system are shown in Table 4 and Table 5.
  • the combination 1 is the data with good consistency between the two modules. It can be seen from the data that the consistency is guaranteed.
  • the input equalization accuracy is less than 1%, and the current sharing accuracy is also within ⁇ 1%. Even if the inconsistency of the two modules is considered, the equalization and current sharing accuracy are within ⁇ 10% accuracy.
  • Table 6 shows the difference between the output voltage of various parameter combinations and the standard output for different input voltages and full output.
  • Table 5 Full-load output current uniformity accuracy of various parameter combinations under different input voltages
  • Table 6 shows the output voltage of various parameter combinations and 12V deviation (V) under different input voltages and full output.
  • the cross feedforward scheme can be fully proved by experiments, which can not only meet the input voltage equalization accuracy and output current sharing accuracy, but more importantly, the output voltage accuracy can be controlled at about 3.5V, achieving both equalizing and equalizing current and reducing the output range.
  • the purpose is to take it to the next level.
  • the circuit shown in FIG. 11 is a circuit schematic diagram of a power supply system according to a second embodiment of the present invention, which is different from the first embodiment in that a module is added to the circuit of the first embodiment to form three modules.
  • the system consists of the primary side series and the secondary side parallel, including: input terminal Vg+, input ground Vg-, output terminal Vo+, output ground Vo-; input capacitors Cin1, Cin2, Cin3; upper module control
  • the circuit 102 the upper module asymmetric half bridge flyback main power circuit 100; the middle module control circuit 202, the middle module asymmetric half bridge flyback main power circuit 200; the lower module control circuit 302, the lower module asymmetric half bridge flyback main Power circuit 300.
  • the upper, middle and lower module control circuits all comprise an isolated sampling circuit, a PWM generating circuit and a driving circuit.
  • the asymmetric half-bridge flyback main power circuit of the upper, middle and lower modules comprises three module MOS tubes S11, S21, S12, S22, S13, S23, DC blocking capacitors Cr1, Cr2, Cr3, transformers 101, 201, 301, Output loop diodes D1, D2, D3, output capacitors C1, C2, C3.
  • the connection relationship is as follows: the input terminal Vg+ is connected to the input ground Vg- through three input capacitors Cin1, Cin2, and Cin3, and the input capacitor Cin1 is respectively connected to the drain of the MOS transistor S11 of the upper module and the source of the MOS transistor S21.
  • the input capacitor Cin2 is respectively connected to the drain of the MOS transistor S12 of the middle module and the source of the MOS transistor S22, and the input capacitor Cin3 is respectively connected to the drain of the MOS transistor S13 of the lower module and the source of the MOS transistor S23, and the upper module
  • the source of the MOS transistor S21 is connected to the drain of the MOS transistor S12 of the middle module
  • the source of the MOS transistor S22 of the middle module is connected to the drain of the MOS transistor S13 of the lower module.
  • the above module is taken as an example.
  • connection mode of the module in the same module is as follows: the source of the MOS transistor S11 of the upper module is connected to the one end 1 of the primary side of the transformer T1 through the DC blocking capacitor Cr1 (through the leakage inductance Lr1 of the transformer T1, the excitation inductance Lm1)
  • the other end 2 of the primary side of the transformer T1 is connected to the source of the MOS transistor S21 of the upper module, and the one end 4 of the secondary side of the transformer T1 is connected to the anode of the output loop diode D1, and the cathode of the output loop diode D1 and the output of the power supply system
  • the positive output of Vo+ is connected, and the other end 3 of the secondary side of transformer T1 is connected to the output of the power system Vo-.
  • the cathode of the output loop diode D2 of the middle module is connected to the positive output terminal of the power supply system output terminal Vo+, and the other end 3 of the secondary side of the transformer T2 is connected to the power system output terminal Vo-.
  • C1 and C2 are connected in parallel between the output terminals Vo+ and Vo-.
  • the open loop control circuit of each module is connected to the driving circuit, and the driving circuit is respectively connected with the upper and lower MOS tubes in the module.
  • the working principle of the second embodiment is the same as that of the first embodiment.
  • the upper module and the middle module perform cross feedforward control
  • the middle module and the lower module perform cross feedforward control
  • the lower module and the upper module perform cross feedforward control.
  • three 60W standard power conversion modules with input voltage range of 120VDC to 240VDC are used as a 180W power supply system in series and parallel connection.
  • the parallel connection effect of three modules input series output under the control of cross feedforward is tested. verification. Considering that the power level and control deviation of the two modules have been verified in the first embodiment, the three modules are nothing but a combination of two and two, and the tolerance effect is the same as that of the two modules, so the embodiment does not perform three Tolerance analysis of the module.
  • the asymmetric half-bridge flyback topology can meet the input voltage equalization accuracy and the output current sharing accuracy. More importantly, the output voltage accuracy can be controlled at about 3.6V, and the average pressure is achieved.
  • the flow, which narrows the scope of the output, is a step higher than the prior art.

Abstract

一种电源系统，包括：不对称半桥反激变换器的第一功率转换模块和第二功率转换模块，第一功率转换模块的负输入端与第二功率转换模块的正输入端相连，第一功率转换模块的正输入端即为系统的正输入端，第二功率转换模块的负输入端即为系统的负输入端；第一功率转换模块的正输出端与第二功率转换模块的正输出端相连，作为系统的正输出端，第一功率转换模块的负输出端与第二功率转换模块的负输出端相连，作为系统的负输出端，由于基于的拓扑是不对称半桥反激变换器，与正激、反激、Royer拓扑相比，具有稳态特性优越、动态小信号容易补偿的特性，并且能够应用到高压下的串并联系统中，获得非常好的输入电压均压精度。

Description

一种电源系统 技术领域
本发明涉及一种电源系统，特别涉及用于高压输入、模块化应用的场合。
背景技术
在开关电源的应用系统中，高压输入场合，如光伏电源，一般其输入范围宽且输入电压高，高压可达到1500V甚至更高，因此需要提高后一级变换器开关管的额定电压。而高压MOSFET的通态电阻大，导致导通损耗大，且成本极高；有人说可以采用IGBT作为开关管，但IGBT饱和压降虽小，但存在电流拖尾现象，限制了开关频率的提高，不利于减小变压器和滤波器件(电感、电容)的体积，再加上成本因素，明显不是好的选择。
为了解决光伏开关电源的高输入电压问题，有些开关电源厂家就想出了在开关电源内部进行功率器件的串并联，用多个低压功率器件来取代所需要的高压应用场合，但是这样的标准开关电源模块限制了用户的选择，一般的厂家为了减少产品型号的数量，都会做超宽范围的输入，导致产品的成本提高，但是对于客户来说却是冗余设计。也有人想到了组合变换器的设计思路，但是一般都是采用复杂的外部控制电路实现的，系统复杂且应用不够灵活。因此，对于电源模块厂家来说能否用标准电源模块直接组成客户端需要的电源系统是值得考虑的问题。如果可以，则可以大大减少电源生产公司所生产的电源品种，方便用户自行设计其需要的供电系统。
用标准电源模块来搭建电源系统，最基本的方法就是采用输入/输出的串并联组合。拿两个完全相同的电源模块作为例子，通过采用输入/输出的串并联方法，共有下列四种电源系统可以组合得到：
系统1：输入并联，输出并联的系统；
系统2：输入串联，输出并联的系统；
系统3：输入并联，输出串联的系统；
系统4：输入串联，输出串联的系统。
这四种系统中，已得到广泛应用的是第一种系统。典型的产品有大功率通信电源系统，大功率UPS系统等，另外三种系统，应用还不多。
系统2中的每个模块，从冗余性要求出发，最好相互独立，即各自有自己的控制与供电。但各个模块不能按单个标准电源一样，做成输出电压的精密稳压，因为 那样的话，各模块在输出端并联后的电流，会由于模块电压的出厂设置值误差，而导致非常大的不均，这也将导致各模块在其输入电压上的极大不均，从而影响模块的可靠性，甚至损坏。所以，一般不能对具有精密稳压的电源模块进行直接的输入串联、输出并联。
在现有常用的拓扑中，正激、反激均从原理上就否决了输入串联输出并联系统的可行性。在常用的拓扑中Royer电路的小信号模型中的输入阻抗为正，较为适合串并联系统中，但是Royer电路用于高压系统中，开关管的选取较为困难，并不适合高压下的串并联系统中。
开关电源作为其他电子设备的能量转换供给单元，其体积与灵活性也备受关注，比如大功率超薄产品，其高压器件的体积以及变压器的体积严重的影响了整体产品的高度。这里有两种解决方式，一种是利用变压器的串并联形式，将功率分散在几个变压器中，减少变压器的体积，从而达到减少整个开关电源体积的目的；另一种思路就是模块的串并联，通过几个小功率模块的串并联而进行功率拓展。但是目前市面上进行两个模块的输入串联输出并联的结构，都需要在模块外额外的添加均流电路，如此应用的外部控制复杂，对于客户来说有一定的专业限制，一些非电子专业的普通客户无法简单的实现。或者通过一些具有正阻抗特性的拓扑，利用其特有自然均压进行原边串联副边并联。
在申请号为201621402396.3的实用新型专利中提及的串并联结构中，采用的是开环控制的不对称半桥反激变换器开关电源模块进行串并联。该专利虽然可以实现两个开关电源模块的简单并联，但是由于负载调整率等原因，整个系统的输出电压范围比输入的电压范围还要大，因此需要添加第二级稳压系统，这对系统的整体效率影响很大。该实用新型专利的电路结构如图1、图2、图3、图4所示，其中图一为两个模块直接输入串联输出并联的结构示意图，图2为两个模块直接输入串联输出并联并添加稳压模块的结构示意图，图3为多个模块直接输入串联输出并联结构示意图，图4为多个模块直接输入串联输出并联并添加稳压模块的结构示意图。
申请号为201621402396.3的实用新型专利中第一实施例采用两个60W，输入电压范围为120VDC～240VDC的标准功率转换模块作为串并联组成一个120W的电源系统，对其在开环控制下的输入串联输出并联效果进行了实验验证。考虑开环控制参数的偏差后，模块的输入电压精度估计会有所下降，此时可将控制参数的两个极端偏差再与功率级参数的两种极端偏差，按模块增益的大小，再组合成一种新的两个 极端模块。从理论上，增益最大和增益最小的这两个模块A和B分别对应下列参数：
增益最大的模块：L m(min)，L r(min)，C r(min)，D mac，f s(min)；
增益最小的模块：L m(max)，L r(max)，C r(max)，D min，f s(max)。
将上述的五个参数组合成以下五组实验参数：
组合1：功率级和控制均为标称参数的输入串联/输出并联实验
A模块参数：L m＝145uH，L r＝7uH，C r＝0.27uF，D＝0.5，f s＝100KHz
B模块参数：L m＝145uH，L r＝7uH，C r＝0.27uF，D＝0.5，f s＝100KHz
组合2：功率级和占空比为标称参数，但开关频率分别为上下偏差的输入串联/输出并联实验
A模块参数：L m＝145uH，L r＝7uH，C r＝0.27uF，D＝0.5，f s＝90KHz
B模块参数：L m＝145uH，L r＝7uH，C r＝0.27uF，D＝0.5，f s＝110KHz
组合3：功率级和开关频率为标称参数，但占空比分别为上下偏差的输入串联/输出并联实验
A模块参数：L m＝145uH，L r＝7uH，C r＝0.27uF，D＝0.55，f s＝100KHz
B模块参数：L m＝145uH，L r＝7uH，C r＝0.27uF，D＝0.45，f s＝100KHz
组合4：开关频率和占空比为标称参数，但功率级参数分别为上下偏差的输入串联/输出并联实验
A模块参数：L m＝130.5uH，L r＝6.3uH，C r＝0.22uF，D＝0.5，f s＝100KHz
B模块参数：L m＝159.5uH，L r＝7.7uH，C r＝0.22uF，D＝0.5，f s＝100KHz
组合5：占空比为标称参数，但功率级参数和开关频率分别为上下偏差的输入串联/输出并联实验
A模块参数：L m＝130.5uH，L r＝6.3uH，C r＝0.22uF，D＝0.55，f s＝90KHz
B模块参数：L m＝159.5uH，L r＝7.7uH，C r＝0.22uF，D＝0.45，f s＝110KHz
系统的输入均压效果与输出均流效果的实验数据如表1与表2所示，组合1是两个模块的一致性很好的数据，从该数据可以看出，在保证了一致性的基础上输入均压精度都在1％以内，均流精度也都在±1％以内，即便是考虑到了两个模块的不一致性，其均压与均流精度也都在±10％的精度内。表3为不同输入电压且输出满载情况下，各种参数组合的输出电压值。
表1不同输入电压下，各种参数组合的最大输入电压均压精度
均压精度 组合1 组合2 组合3 组合4 组合5
Vg＝300V ±0.67％ ±1.23％ ±8.7％ ±6.8％ ±5.6％
Vg＝400V ±0.38％ ±1.20％ ±8.2％ ±6.8％ ±5.5％
Vg＝530V ±0.15％ ±1.21％ ±8.0％ ±6.9％ ±5.6％
表2不同输入电压下，各种参数组合的满载输出电流均流精度
均流精度 组合1 组合2 组合3 组合4 组合5
Vg＝300V ±0.10％ ±0.92％ ±8.5％ ±6.6％ ±6.1％
Vg＝400V ±0.12％ ±1.30％ ±7.9％ ±7.0％ ±7.4％
Vg＝530V ±0.25％ ±1.63％ ±7.6％ ±7.3％ ±6.9％
表3不同输入电压且输出满载情况下，各种参数组合的输出电压(V)
输出电压 组合1 组合2 组合3 组合4 组合5
Vg＝300V 13.99 13.97 13.95 13.63 14.52
Vg＝400V 19.28 19.25 19.24 18.81 19.99
Vg＝530V 25.93 25.91 25.89 25.26 26.81
从以上三个表格中可以看出，两个模块输入串联输出并联后可以满足两个模块的输入均压与输出均流精度，但是输出电压范围却大于输入电压范围，目前ACDC的母线电压范围为5:1左右，那么后级的稳压模块的设计难度极大。
为了解决输出电压范围宽的问题，一般想到的是添加前馈电路，对于占空比不随输出负载变化而变化的拓扑，可以通过检测其自身的输入电压，来改变主控IC的占空比大小，从而实现不同输入电压下，单独模块输出电压稳定，实现了模块的预稳压。在这种双模块输入串联，输出并联系统中，实现最简单的输入前馈就是让每个模块的占空比与其自己的输入电压成反比。下面我们来分析一下添加自前馈单元对模块阻抗特性的影响。
在输入自前馈这种控制方式中，当其中一个模块的输入电压升高时，该模块的占空比就会减少，而占空比的下降又会导致该模块输出功率的减少，从而导致该模块输入功率的减少，最终使这个模块输入电容两端的电压，也即模块的输入电压继续升高，形成了正反馈，如此不断循环，模块的输入电压会越来越高，最终会导致两个模块输入电压的极度不均，难以实现要求的输入均压精度，其过程可用图5来描述。
通过上面的定性分析可以知道，进行自前馈这种控制，可以减小输出电压的范围，但无法实现各模块输入电压的均压精度及输出电流的均流精度，从图5中明显 可以看出，单个模块进行自前馈，无法满足模块输入串联输出并联系统的输入均压、输出均流精度。同样的采用输出电压闭环进行占空比调节也会改变模块的输入阻抗特性，无法满足输入串联输出并联系统的输入均压、输出均流精度。
发明内容
本发明要解决的技术问题为：一种电源系统，实现输入串联和输出并联这种电源系统中的输入均压，输出均流要求，并能实现输出电压基本稳定，不随输入变化而变化，实现多个模块的直接串并联，使电源系统更加灵活，相比两级方案，效率更高。引入模块化思想，输入级采用多个模块串联方式，如此每个模块的电压应力就会大大降低。
为了达到上述目的，本发明是通过以下技术方案实现的：
一种电源系统，包括N个功率转换模块，N为大于1的自然数，所述的N个功率转换模块均为开环控制的不对称半桥反激变换器，其连接关系为：第一功率转换模块的正输入端作为系统的正输入端，第一功率转换模块的负输入端与第二功率转换模块的正输入端相连，第二功率转换模块的负输入端与第三功率转换模块的正输入端相连，依次类推，第N-1功率转换模块的负输入端与第N功率转换模块的正输入端相连，第N功率转换模块的负输入端作为系统的负输入端；所述的N个功率转换模块的正输出端连接后作为系统的正输出端，所述的N个功率转换模块的负输出端连接后作为系统的负输出端；其特征在于：第一功率转换模块与第二功率转换模块进行交叉前馈控制，第二功率转换模与第三功率转换模进行交叉前馈控制，依次类推，第N-2功率转换模块与第N-1功率转换模块进行交叉前馈控制，第N功率转换模块与第一功率转换模块进行交叉前馈控制。
优选地，不对称半桥反激变换器包括：正输入端、负输入端、正输出端、负输出端、第一滤波电容、第一开关管、第二开关管、控制电路、谐振电容、功率器件、输出整流二极管、第二滤波电容；功率器件包括：变压器、变压器的漏感和变压器的励磁电感；第一滤波电容跨接在正输入端和负输入端之间，第一开关管的导通电流流出端与第二开关管的导通电流流入端连接，第一开关管的导通电流流入端连接到正输入端，第二开关管的导通电流流出端连接到负输入端，谐振电容的一端连接在第一开关管的导通电流流出端，另一端连接在变压器原边的同名端，变压器原边的异名端连接到负输入端，变压器副边的异名端与输出整流二极管的阳极相连，第二滤波电容的一端连接到输出整流二极管的阴极，作为正输出端，第二滤波电容的 另一端连接到变压器副边的同名端，作为负输出端；控制电路包括PWM发生电路、驱动电路、隔离采样电路，隔离采样电路用来等比例采样输入电压，驱动电路连接第一开关管和第二开关管的控制端，PWM发生电路输出PWM信号给驱动电路用来控制第一开关管与第二开关管。
优选地，第一开关管和第二开关管为MOS管或三极管。
优选地，第一开关管和第二开关管的驱动脉冲信号之间错开一防止共通短路的死区时间。
优选地，所述的死区时间为300nS。
名词解释：
交叉前馈控制：采用其他电源模块的前馈信号控制本身的占空比，比如两个电源模块的输入串联输出并联系统，第一个电源模块的前馈信号接入第二个电源模块的占空比控制电路中控制第一个电源模块的占空比，第二个电源模块的前馈信号接入第一个电源模块的占空比控制电路中控制第二个电源模块的占空比。
开关管的控制端：控制反馈开关导通与截止的端口，如对于MOS管，指的是MOS管的栅极；对于三极管，指的是三极管的基极。
开关管的导通电流流入端：开关管导通后，电流流入的端口，如对于MOS管，指的是MOS管的漏极，无论N沟道、P沟道、增强型还是耗尽型MOS管，在导通时，电流都是由电压高的漏极流向电压低的源极；对于三极管，指的是三极管的集电极，在导通时，电流是由电压高的集电极流向电压低的发射极。
开关管的导通电流流出端：开关管导通后，电流流出的端口，如对于MOS管，指的是MOS管的源极；对于三极管，指的是三极管的发射极。
前馈信号：通过检测电源模块自身的输入电压获得的信号。
与现有技术相比，本发明具有以下有益效果：
(1)、输入串联输出并联系统的输出电压浮动范围小
(2)、输入串联输出并联系统的实现方式简单，只需几条连线即可实现模块的串并联；
(3)、本发明采用了模块化思维，将系统拆分成N个相同的标准模块；
(4)、单个标准化模块的电压应力及电流应力低，可以降低器件成本；
(5)、用户可以按照需求直接使用标准模块自由组建系统，使用灵活，可移植性高，且该系统对客户的要求低，直接将模块的输入串联、输出并联即可，不需要 本专业的专业知识；
(6)、使用标准电源模块组成所需电源系统，减少产品型号、降低产品管理成本；
(7)、每个标准模块之间采用直流电压信号，多模块输入串联、输出并联系统很容易布板，不会产生相互间的干扰。
附图说明
图1申请号为201621402396.3的实用新型专利双模块输入串联输出并联系统框图；
图2申请号为201621402396.3的实用新型专利带有稳压模块的双模块输入串联输出并联系统框图；
图3申请号为201621402396.3的实用新型专利N个标准模块的输入串联输出并联系统框图；
图4申请号为201621402396.3的实用新型专利带有稳压模块的N个标准模块的输入串联输出并联系统框图；
图5自反馈方式的原边串联副边并联系统的理论分析过程示意图；
图6交叉反馈方式的原边串联副边并联系统的理论分析过程示意图；
图7本发明的单个模块电路原理图；
图8本发明双模块输入串联输出并联系统框图；
图9本发明N个标准模块的输入串联输出并联系统框图；
图10第一实施例电路原理框图；
图11第二实施例电路原理图。
具体实施方式
本申请的发明人通过对不对称半桥反激变换器的前馈控制方式研究，得出了一种新的前馈控制构思，即前文所定义的“交叉前馈控制”，通过每个不对称半桥反激变换器的正阻抗特性，控制电源系统中每个功率转换模块的输入均压，从而实现电源系统的输出均流，输入交叉前馈控制对输入电压不仅具有前馈控制的作用，还能自动矫正模块输入电压的不平衡程度，下面简要说明这个矫正过程：
如图6所示，有两个模块，A模块、B模块，假设A模块的输入电压因某种原因变高，则B模块的输入电压会同步变低。输入电压变高的A模块，通过对其输入电压的隔离取样后，去控制B模块的占空比，使其占空比减小；同样，输入电压变低的B模 块，通过对其输入电压的隔离取样后，去控制A模块的占空比，使其占空比增加。如此控制的结果是，输入电压变高的A模块因占空比增加，导致输入功率增加，从而导致其输入电容两端电压，也即该模块(A模块)输入电压的下降；输入电压变低的B模块因占空比减小，导致输入功率减小，从而导致其输入电容两端电压，也即该模块输入电压的增加；如此，两个模块的输入电压都会朝着原来的变化之反方向变化，即输入电压增加的模块，通过交叉前馈控制，会使输入电压减少；输入电压减少的模块，通过交叉前馈控制，会使输入电压增加。所以输入交叉前馈控制具有自动矫正模块输入电压到平衡的功能。
图7为本发明的单个模块电路原理图，采用的是不对称半桥反激变换器：包括两个输入端(Vg1、输入地)、两个输出端(Vo、输出地)、第一滤波电容Cin1、第一开关管S11、第二开关管S21、控制电路102、谐振电容Cr1、功率器件101(包括变压器T1、变压器T1的漏感Lr1和励磁电感Lm1)、输出整流二极管D1、第二滤波电容C1，所述的第一滤波电容Cin1跨接在两个输入端之间，第一开关管S11的导通电流流出端与第二开关管S21的导通电流流入端连接，然后第一开关管S11的导通电流流入端连接到输入端的Vg1，第二开关管S21的导通电流流出端连接到输出端的输出地，谐振电容Cr1的一端连接在第一开关管S11的导通电流流出端，另一端连接在变压器T1原边同名端，变压器T1原边的异名端连接到输出端的输出地，变压器T1副边的异名端与输出整流二极管D1的阳极相连，第二滤波电容C1的一端连接到输出整流二极管D1的阴极，作为输出端的Vo，第二滤波电容C1的另一端连接到变压器T1副边的同名端，作为输出端的输出地，控制电路102包括PWM发生电路、驱动电路、隔离采样电路，用来控制第一开关管S11与第二开关管S21，隔离采样电路用来等比例采样输入电压。
图8为本发明双模块输入串联输出并联系统框图、图9本发明N个标准模块的输入串联输出并联系统框图。
单使用文字描述原理，会让本技术领域人员理解困难，所以，请允许使用原理图，配合电子工程中常用的信号流向来说明本发明的工作原理。为描述方便，图中各模块编号和元器件代号按一定规则进行编码，其中第一个数字表示元器件代号，第二个数字表示模块编号，如开关管S11，第一个1代表S1开关管(或称为第一开关管)，第二个1表示为第一个模块中的S1开关管；开关管S12表示是第二个模块中的第一开关管；开关管S21表示是第一模块中的S2开关管，开关管S22表示是第二模块 中的S2开关管。需注意的是，为方便起见，下文在某些场合下可能省略其中表示模块编号的第二个数字，而仅保留作为元器件代号的第一个数字。以下详细说明本发明的具体实施例。
第一实施例
如图10所示，为第一实施例电路原理框图，由两个图7所示的单个模块电路采用交叉控制的方式串并联组成，包括：输入端Vg+、输入地Vg-，输出端Vo+、输出地Vo-；输入电容Cin1、Cin2；上模块控制电路102，上模块不对称半桥反激主功率电路100；下模块控制电路202，下模块不对称半桥反激主功率电路200。其中上、下模块控制电路都包含有隔离采样电路、PWM发生电路、驱动电路。上、下模块的不对称半桥反激主功率电路包含两个模块MOS管S11、S21、S12、S22，隔直电容Cr1、Cr2，变压器101、201，输出回路二极管D1、D2，输出电容C1、C2。其连接关系为：输入端Vg+通过两个输入电容Cin1、Cin2后，接入到输入地Vg-，输入电容Cin1分别与上模块的MOS管S11的漏极和MOS管S21的源极连接，输入电容Cin2分别与下模块的MOS管S12的漏极和MOS管S22的源极连接，上模块的MOS管S21的源极与下模块的MOS管S12的漏极连接。以上模块为例，下模块同上模块的连接方式为：上模块的MOS管S11的源极通过隔直电容Cr1，与变压器T1原边的一端1相连(通过变压器T1的漏感Lr1、励磁电感Lm1)，该变压器T1原边的另一端2与上模块的MOS管S21的源极连接，变压器T1副边的一端4与输出回路二极管D1的阳极连接，输出回路二极管D1的阴极与电源系统输出端Vo+的正输出端连接，变压器T1副边的另一端3连接到电源系统输出端Vo-。下模块的输出回路二极管D2的阴极与电源系统输出端Vo+的正输出端连接，变压器T2副边的另一端3连接到电源系统输出端Vo-。C1、C2并接于输出端Vo+与Vo-之间。每个模块的开环控制电路连接驱动电路，驱动电路分别与模块中的上下两个MOS管连接。
工作原理：
在该实施例中，整个系统由上下两个功率转换模块串联输入、并联输出组成，单个功率转换模块的主功率级工作原理同不对称半桥反激电路，这对于本领域的技术人员而言是公知技术，在此不展开。控制过程如下：将输入串联、输出并联系统中上模块的输入电压，通过线性降压隔离，其隔离后的电压信号作为下模块的占空比前馈控制信号。同样，将输入串联、输出并联系统中下模块的输入电压，通过线 性降压隔离，其隔离后的电压信号作为下模块的占空比前馈控制信号。为了避免单个功率转换模块的两个开关管出现共通短路现象，给上、下开关管的驱动脉冲信号之间添加300nS的死区时间。输入交叉前馈对输入电压不仅具有前馈控制的作用，还能自动矫正模块输入电压的不平衡程度。
本实施例用两个60W，输入电压范围为120VDC～240VDC的标准功率转换模块作为串并联组成一个120W的电源系统，为了充分验证交叉前馈在容差下对输入均压精度及输出均流精度的影响，对其进行了容差实验验证。将控制参数的两种极端偏差与功率级参数的两种极端偏差，按功率转换模块增益的大小，再组合成一种新的两种极端偏差的模块。从理论上，增益最大和增益最小的这两个模块分别对应下列参数：
增益最大的模块：励磁电感最小值，漏感最小值，谐振电容最小值，频率最小值，即：L m(min),L r(min),C r(min),f s(min)；
增益最小的模块：励磁电感最大值，漏感最大值，谐振电容最大值，频率最大值，即：L m(max),L r(max),C r(max),f s(max)。
将上述的四个参数组合成以下四组实验参数：
组合1：功率级和控制均为标称参数的输入串联/输出并联实验
上模块参数：L m1＝145μH,L r1＝6.37μH,C r1＝0.27μF,f s1＝100KHz
下模块参数：L m＝145μH,L r＝6.37μH,C r＝0.27μF,f s＝100KHz
组合2：功率级为标称参数，但开关频率分别为上下偏差的输入串联/输出并联实验
上模块参数：L m＝145μH,L r＝6.37μH,C r＝0.27μF,f s＝90KHz
下模块参数：L m＝145μH,L r＝6.37μH,C r＝0.27μF,f s＝110KHz
组合3：开关频率为标称参数，但功率级参数分别为上下偏差的输入串联/输出并联实验
上模块参数：L m＝130.5μH,L r＝5.733μH,C r＝0.216μF,f s＝100KHz
下模块参数：L m＝159.5μH,L r＝7.007μH,C r＝0.324μF,f s＝100KHz
组合4：功率级参数和开关频率分别为上下偏差的输入串联/输出并联实验
上模块参数：L m＝130.5μH,L r＝5.733μH,C r＝0.216μF,f s＝90KHz
下模块参数：L m＝159.5μH,L r＝7.007μH,C r＝0.324μF,f s＝110KHz
系统的输入均压效果与输出均流效果的实验数据如表4与表5所示，组合1是两个模块的一致性很好的数据，从该数据可以看出，在保证了一致性的基础上输入均压精度都在1％以内，均流精度也都在±1％以内，即便是考虑到了两个模块的不一致性，其均压与均流精度也都在±10％的精度内。表6为不同输入电压且输出满载情况下，各种参数组合的输出电压与标准输出的差值。
表4不同输入电压下，各种参数组合的最大输入电压均压精度
均压精度 组合1 组合2 组合3 组合4
V g＝300V ±0.8％ ±4.8％ ±4.8％ ±5.2％
V g＝400V ±1.1％ ±4.3％ ±4.3％ ±5.5％
V g＝530V ±1.1％ ±4.5％ ±4.5％ ±5.6％
表5不同输入电压下，各种参数组合的满载输出电流均流精度
均流精度 组合1 组合2 组合3 组合4
V g＝300V ±1.7％ ±3.1％ ±5.5％ ±5.9％
V g＝400V ±1.6％ ±4.2％ ±4.6％ ±6％
V g＝530V ±1.9％ ±4.2％ ±4.8％ ±6.4％
表6不同输入电压且输出满载情况下，各种参数组合的输出电压与12V偏差(V)
输出电压 组合1 组合2 组合3 组合4
V g＝300V 2.89 3.21 3.24 3.35
V g＝400V 2.94 3.12 3.12 3.28
V g＝530V 3.01 3.16 3.17 3.41
通过实验可以充分证明交叉前馈方案，不但可以满足输入均压精度以及输出均流精度，更重要的是输出电压精度能控制在3.5V左右，实现了既均压均流，又缩小了输出范围的目的，比现有技术更上一层楼。
第二实施例
图11所示的电路为本发明第二实施例的电源系统的电路原理图，与第一实施例的区别之处在于：在第一实施例电路基础上又添加了一个模块，构成三个模块(上、中、下模块)构成的原边串联副边并联的系统，包括：输入端Vg+、输入地Vg-，输 出端Vo+、输出地Vo-；输入电容Cin1、Cin2、Cin3；上模块控制电路102，上模块不对称半桥反激主功率电路100；中模块控制电路202，中模块不对称半桥反激主功率电路200；下模块控制电路302，下模块不对称半桥反激主功率电路300。其中上、中及下模块控制电路都包含有隔离采样电路、PWM发生电路、驱动电路。上、中及下模块的不对称半桥反激主功率电路包含三个模块MOS管S11、S21、S12、S22、S13、S23，隔直电容Cr1、Cr2、Cr3，变压器101、201、301，输出回路二极管D1、D2、D3，输出电容C1、C2、C3。其连接关系为：输入端Vg+通过三个输入电容Cin1、Cin2、Cin3后，接入到输入地Vg-，输入电容Cin1分别与上模块的MOS管S11的漏极和MOS管S21的源极连接，输入电容Cin2分别与中模块的MOS管S12的漏极和MOS管S22的源极连接，输入电容Cin3分别与下模块的MOS管S13的漏极和MOS管S23的源极连接，上模块的MOS管S21的源极与中模块的MOS管S12的漏极连接、中模块的MOS管S22的源极与下模块的MOS管S13的漏极连接。以上模块为例，中模块同上模块的连接方式为：上模块的MOS管S11的源极通过隔直电容Cr1，与变压器T1原边的一端1相连(通过变压器T1的漏感Lr1、励磁电感Lm1)，该变压器T1原边的另一端2与上模块的MOS管S21的源极连接，变压器T1副边的一端4与输出回路二极管D1的阳极连接，输出回路二极管D1的阴极与电源系统输出端Vo+的正输出端连接，变压器T1副边的另一端3连接到电源系统输出端Vo-。中模块的输出回路二极管D2的阴极与电源系统输出端Vo+的正输出端连接，变压器T2副边的另一端3连接到电源系统输出端Vo-。C1、C2并接于输出端Vo+与Vo-之间。每个模块的开环控制电路连接驱动电路，驱动电路分别与模块中的上下两个MOS管连接。
第二实施例的工作原理与第一实施例的原理相同，上模块与中模块进行交叉前馈控制，中模块与下模块进行交叉前馈控制，下模块与上模块进行交叉前馈控制。
本实施例采用三个60W，输入电压范围为120VDC～240VDC的标准功率转换模块作为串并联组成一个180W的电源系统，对其在交叉前馈的控制下三个模块输入串联输出并联效果进行了实验验证。考虑到第一实施例已经对两个模块的功率级以及控制偏差进行了验证，故三个模块无非就是两两组合，容差影响与两个模块的相同，故该实施例便没有进行三个模块的容差分析。
三个模块均取功率级参数L m＝145μH,L r＝6.37μH,C r＝0.27μF,D＝0.5,f s＝100KHz，实验结果如表7所示：
表7三模块实验结果
Figure PCTCN2018090365-appb-000001
通过实验可以充分证明不对称半桥反激拓扑在开环条件下，可以满足输入均压精度以及输出均流精度，更重要的是输出电压精度能控制在3.6V左右，实现了既均压均流，又缩小了输出范围的目的，比现有技术更上一层楼。
以上仅是本发明的优选实施方式，应当指出的是，上述优选实施方式不应视为对本发明的限制。对于本技术领域的普通技术人员来说，在不脱离本发明的精神和范围内，还可以做出若干改进和润饰，这些改进和润饰也应视为本发明的保护范围，这里不再用实施例赘述，本发明的保护范围应当以权利要求所限定的范围为准。

Claims (5)

  1. 一种电源系统，包括N个功率转换模块，N为大于1的自然数，所述的N个功率转换模块均为开环控制的不对称半桥反激变换器，其连接关系为：第一功率转换模块的正输入端作为系统的正输入端，第一功率转换模块的负输入端与第二功率转换模块的正输入端相连，第二功率转换模块的负输入端与第三功率转换模块的正输入端相连，依次类推，第N-1功率转换模块的负输入端与第N功率转换模块的正输入端相连，第N功率转换模块的负输入端作为系统的负输入端；所述的N个功率转换模块的正输出端连接后作为系统的正输出端，所述的N个功率转换模块的负输出端连接后作为系统的负输出端；其特征在于：第一功率转换模块与第二功率转换模块进行交叉前馈控制，第二功率转换模与第三功率转换模进行交叉前馈控制，依次类推，第N-2功率转换模块与第N-1功率转换模块进行交叉前馈控制，第N功率转换模块与第一功率转换模块进行交叉前馈控制。
  2. 根据权利要求1所述的电源系统，其特征在于：不对称半桥反激变换器包括：正输入端、负输入端、正输出端、负输出端、第一滤波电容、第一开关管、第二开关管、控制电路、谐振电容、功率器件、输出整流二极管、第二滤波电容；功率器件包括：变压器、变压器的漏感和变压器的励磁电感；第一滤波电容跨接在正输入端和负输入端之间，第一开关管的导通电流流出端与第二开关管的导通电流流入端连接，第一开关管的导通电流流入端连接到正输入端，第二开关管的导通电流流出端连接到负输入端，谐振电容的一端连接在第一开关管的导通电流流出端，另一端连接在变压器原边的同名端，变压器原边的异名端连接到负输入端，变压器副边的异名端与输出整流二极管的阳极相连，第二滤波电容的一端连接到输出整流二极管的阴极，作为正输出端，第二滤波电容的另一端连接到变压器副边的同名端，作为负输出端；控制电路包括PWM发生电路、驱动电路、隔离采样电路，隔离采样电路用来等比例采样输入电压，驱动电路连接第一开关管和第二开关管的控制端，PWM发生电路输出PWM信号给驱动电路用来控制第一开关管与第二开关管。
  3. 根据权利要求2所述的电源系统，其特征在于：第一开关管和第二开关管为MOS管或三极管。
  4. 根据权利要求2所述的电源系统，其特征在于：第一开关管和第二开关管的驱动脉冲信号之间错开一防止共通短路的死区时间。
  5. 根据权利要求5所述的电源系统，其特征在于：所述的死区时间为300nS。
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Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN109888768A (zh) * 2019-03-21 2019-06-14 深圳供电局有限公司 接口装置以及电源系统
CN115694192A (zh) * 2021-07-26 2023-02-03 中兴通讯股份有限公司 电压转换电路、控制方法、电源装置及存储介质
CN116345718A (zh) * 2023-03-31 2023-06-27 重庆大学 原边多模块副边多模块的mc-wpt系统及其副边切换方法
CN115694192B (zh) * 2021-07-26 2024-04-26 中兴通讯股份有限公司 电压转换电路、控制方法、电源装置及存储介质

Families Citing this family (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN107276417A (zh) * 2017-08-09 2017-10-20 广州金升阳科技有限公司 一种电源系统
CN110277917B (zh) * 2018-03-13 2021-06-18 比亚迪股份有限公司 轨道交通供电系统及其双向dc-dc变换器和控制方法
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CN110518796B (zh) * 2019-09-24 2020-06-23 四川灵通电讯有限公司 直流恒流转直流恒流的多模块电源控制装置及应用方法
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CN114825941B (zh) * 2022-06-20 2022-09-09 麦田能源有限公司 电源变换系统、变换装置的控制方法及反激电源变换系统

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20080197825A1 (en) * 2007-02-21 2008-08-21 Kasemsan Siri Uniform converter input voltage distribution power system
CN102437739A (zh) * 2011-12-14 2012-05-02 深圳市元正能源系统有限公司 减小变换器串联拓扑原端电容电压差值的方法和控制电路
CN102664530A (zh) * 2012-04-27 2012-09-12 南京航空航天大学 软开关隔离型开关电容调节器
CN106505865A (zh) * 2016-11-21 2017-03-15 广州金升阳科技有限公司 一种不对称半桥反激变换器及其驱动控制方法
CN107276417A (zh) * 2017-08-09 2017-10-20 广州金升阳科技有限公司 一种电源系统

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN207283409U (zh) * 2017-08-09 2018-04-27 广州金升阳科技有限公司 一种电源系统

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20080197825A1 (en) * 2007-02-21 2008-08-21 Kasemsan Siri Uniform converter input voltage distribution power system
CN102437739A (zh) * 2011-12-14 2012-05-02 深圳市元正能源系统有限公司 减小变换器串联拓扑原端电容电压差值的方法和控制电路
CN102664530A (zh) * 2012-04-27 2012-09-12 南京航空航天大学 软开关隔离型开关电容调节器
CN106505865A (zh) * 2016-11-21 2017-03-15 广州金升阳科技有限公司 一种不对称半桥反激变换器及其驱动控制方法
CN107276417A (zh) * 2017-08-09 2017-10-20 广州金升阳科技有限公司 一种电源系统

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN109888768A (zh) * 2019-03-21 2019-06-14 深圳供电局有限公司 接口装置以及电源系统
CN115694192A (zh) * 2021-07-26 2023-02-03 中兴通讯股份有限公司 电压转换电路、控制方法、电源装置及存储介质
CN115694192B (zh) * 2021-07-26 2024-04-26 中兴通讯股份有限公司 电压转换电路、控制方法、电源装置及存储介质
CN116345718A (zh) * 2023-03-31 2023-06-27 重庆大学 原边多模块副边多模块的mc-wpt系统及其副边切换方法
CN116345718B (zh) * 2023-03-31 2024-04-16 重庆大学 原边多模块副边多模块的mc-wpt系统及其副边切换方法

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