Summary of the invention
The object of the present invention is to provide a kind of inverter input stage circuit of wide range input voltage, narrow to solve in the prior art input voltage range, can not satisfy the problem of the job requirement of inverter.
The embodiment of the invention provides a kind of inverter input stage circuit of wide range input voltage, described circuit comprises the first switching tube Q1, second switch pipe Q2, the first inductance L 1, the controlling of sampling module, by-pass switch K1 and mode selection switch K 2, the input of described the first switching tube Q1 links to each other with input voltage is anodal, the output of the first switching tube connects described the first inductance L 1 and described second switch pipe Q2, the output of described second switch pipe links to each other with the dc bus negative terminal of inverter input stage, the other end of the first inductance L 1 connects the negative pole of input voltage and the dc bus anode of inverter input stage, the magnitude of voltage of described controlling of sampling module Gather and input circuit and respectively with the first switching tube Q1, the control end of second switch pipe Q2 links to each other and alternately controls its switching, the model selection pin of described mode selection switch K2 links to each other with the input voltage negative pole, pattern 1 pin of mode selection switch K2 connects dc bus anode and the by-pass switch K1 of inverter input stage, the other end of by-pass switch K1 connects the positive pole of input voltage, pattern 2 pins of mode selection switch K2 connect the dc bus negative terminal of inverter input stage, and the control end of by-pass switch K1 and mode selection switch K2 links to each other with the controlling of sampling module.
The embodiment of the invention also provides the inverter of another kind of wide range input voltage, the dc bus module and the inversion module that comprise the inverter input stage, the dc bus module of described inverter input stage links to each other with inversion module, directly also be connected with input stage circuit between busbar modules and input circuit, described input stage circuit comprises: directly also be connected with input stage circuit between busbar modules and input circuit, described input stage circuit comprises: described circuit comprises the first switching tube Q1, second switch pipe Q2, the first inductance L 1, the controlling of sampling module, by-pass switch K1 and mode selection switch K 2, the input of described the first switching tube Q1 links to each other with input voltage is anodal, the output of the first switching tube connects the first inductance L 1 and second switch pipe Q2, the output of second switch pipe links to each other with the dc bus negative terminal of inverter input stage, the other end of the first inductance L 1 connects the negative pole of input voltage and the dc bus anode of inverter input stage, the magnitude of voltage of described controlling of sampling module Gather and input circuit and respectively with the first switching tube Q1, the control end of second switch pipe Q2 links to each other and alternately controls its switching, the model selection pin of described mode selection switch K2 links to each other with the input voltage negative pole, pattern 1 pin of mode selection switch K2 connects dc bus anode and the by-pass switch K1 of inverter input stage, the other end of by-pass switch K1 connects the positive pole of input voltage, pattern 2 pins of mode selection switch K2 connect the dc bus negative terminal of inverter input stage, and the control end of by-pass switch K1 and mode selection switch K2 links to each other with the controlling of sampling module.
The embodiment of the invention also provides the inverter of a kind of inverter input stage circuit according to above-mentioned wide range input voltage or above-mentioned wide range input voltage to realize the method for wide voltage input, and described method comprises the steps:
The magnitude of voltage of described controlling of sampling module Gather and input circuit;
The input voltage that the gathers voltage range with the dc bus permission of inverter input stage is compared;
When the input voltage that gathers was lower than the minimum voltage value of the voltage range that the dc bus of inverter input stage allows, the controlling of sampling module improved the dutyfactor value of the first switching tube Q1;
When the input voltage that gathers was higher than the maximum voltage value of the voltage range that the dc bus of inverter input stage allows, the controlling of sampling module reduced the dutyfactor value of the first switching tube Q1;
When the input voltage that gathers is in the voltage range of the dc bus permission of inverter input stage, controlling of sampling module controls by-pass switch K1 conducting, mode selection switch K2 switches to bypass mode.
The inverter input stage circuit of the described wide range input voltage of the embodiment of the invention, can be by the controlling of sampling module to the first switching tube Q1, second switch pipe Q2 carries out periodic open and close controlling, when control the first switching tube Q1 conducting, when second switch pipe Q2 closes, input voltage charges to the first inductance L 1, when control second switch pipe Q2 conducting, when the first switching tube Q1 closes, discharged by 1 pair of output loading of the first inductance L, when being detected input voltage by the controlling of sampling module and surpass or be lower than the voltage range that the dc bus of inverter input stage allows, the duty ratio of controlling of sampling module controls output control pulse, the range of voltage values that allows from the dc bus that makes output voltage adjust to the inverter input stage, thereby when wider input voltage range, the input stage circuit output voltage stabilization, inverter can be worked, and when input voltage value is in the scope that the dc bus of inverter input stage allows, control model selector switch K2 and by-pass switch K1 form path, input voltage is directly loaded on the dc bus of inverter input stage, thereby reduce inductance L 1, switch Q1, loss on the Q2 improves inverter efficiency.
Embodiment
In order to make purpose of the present invention, technical scheme and advantage clearer, below in conjunction with drawings and Examples, the present invention is further elaborated.Should be appreciated that specific embodiment described herein only in order to explain the present invention, is not intended to limit the present invention.
Embodiment one:
Fig. 2 shows the inverter input stage circuit structure of the wide range input voltage that the embodiment of the invention provides, and for convenience of explanation, only shows the part relevant with the embodiment of the invention, and details are as follows.
The described inverter input stage circuit of present embodiment, comprise the first switching tube Q1, second switch pipe Q2, the first inductance L 1, the controlling of sampling module, by-pass switch K1 and mode selection switch K 2, the input of described the first switching tube Q1 links to each other with input voltage is anodal, the output of the first switching tube connects the first inductance L 1 and second switch pipe Q2, the output of second switch pipe links to each other with the dc bus negative terminal of inverter input stage, the other end of the first inductance L 1 connects the negative pole of input voltage and the dc bus anode of inverter input stage, the magnitude of voltage of described controlling of sampling module Gather and input circuit and respectively with the first switching tube Q1, the control end of second switch pipe Q2 links to each other and alternately controls its switching, the model selection pin of described mode selection switch K2 links to each other with the input voltage negative pole, pattern 1 pin of mode selection switch K2 connects dc bus anode and the by-pass switch K1 of inverter input stage, the other end of by-pass switch K1 connects the positive pole of input voltage, pattern 2 pins of mode selection switch K2 connect the dc bus negative terminal of inverter input stage, and the control end of by-pass switch K1 and mode selection switch K2 links to each other with the controlling of sampling module.
Input stage circuit according to the inverter of above-mentioned wide range input voltage, can adjust flexibly according to the voltage of input the duty ratio that alternately opens and closes of the first switching tube Q1 and second switch pipe Q2, thereby make circuit enter into corresponding boost mode or decompression mode, its operation principle is as follows:
Whole control cycle t comprises t1 and t2 two parts, among the forward part time t1 of control cycle, the first switching tube Q1 conducting, second switch pipe Q2 cut-off, input voltage charges to the first inductance L 1 through the first switching tube, load this moment provides energy by the capacitor discharge in parallel with it, in the rear section time of control cycle t2, the first switching tube Q1 cut-off, second switch pipe Q2 conducting, at this moment, input voltage stops to 1 charging of the first inductance L, the first inductance is discharged by 1 pair of load of the first inductance L in rear section time t2 through after the charging of forward part time t1.The purpose of the afterflow of selecting second switch pipe Q2 herein and need not be common is, during the switching tube conducting pressure drop little, the power loss that causes in the time of can reducing the voltage transitions of inverter improves the voltage transitions efficient of input stage circuit.By adjusting the dutyfactor value of the first switching tube, can realize the magnitude of voltage to the output of input stage circuit, thereby make in the voltage range that its dc bus that remains on the inverter input stage allows.Thereby when wider input voltage range, the input stage circuit output voltage stabilization, inverter can be worked, and when input voltage value is in the scope that the dc bus of inverter input stage allows, control model selector switch K2 and by-pass switch K1 form path, input voltage is directly loaded on the dc bus of inverter input stage, thereby reduce the loss on inductance L 1, switch Q1, the Q2, improve inverter efficiency.
Embodiment two:
As shown in Figure 3, the inverter input stage circuit structural representation of the wide range input voltage that provides for second embodiment of the invention, details are as follows:
The inverter input stage circuit of the described wide range input voltage of present embodiment comprises the first switching tube Q1, second switch pipe Q2, the first inductance L 1, controlling of sampling module, by-pass switch K1, mode selection switch K
2 and filter capacitor C1.The input of described the first switching tube Q1 links to each other with input voltage is anodal, the output of the first switching tube connects the first inductance L 1 and second switch pipe Q2, the output of second switch pipe links to each other with the dc bus negative terminal of inverter input stage, the other end of the first inductance L 1 connects the negative pole of input voltage and the dc bus anode of inverter input stage, and the magnitude of voltage of described controlling of sampling module Gather and input circuit also links to each other with the control end of the first switching tube Q1, second switch pipe Q2 respectively and alternately controls its switching; Described the first switching tube Q1 and second switch pipe Q2 are parallel with respectively a diode, and the negative electrode of diode links to each other with the input of its switching tube in parallel, and the anode of diode links to each other with the output of its paralleling switch pipe; The model selection pin of described mode selection switch K2 links to each other with the input voltage negative pole, pattern 1 pin of mode selection switch K2 connects dc bus anode and the by-pass switch K1 of inverter input stage, the other end of by-pass switch K1 connects the positive pole of input voltage, pattern 2 pins of mode selection switch K2 connect the dc bus negative terminal of inverter input stage, and the control end of by-pass switch K1 and mode selection switch K2 links to each other with the controlling of sampling module; It is anodal that the end of described filter capacitor C1 connects input voltage, and the other end connects the negative pole of input voltage.
Wherein, described controlling of sampling module as shown in Figure 4, it comprises sampling module 31, controller 32, modulation circuit 33, via sending corresponding control command to modulation circuit 33 after controller 32 computings, drives corresponding the first switching tube Q1 and second switch pipe Q2 by modulation circuit 33.Described sampling module 31 comprises input voltage value, input current value, output voltage values etc. with the data that collect, size according to input voltage, controller calculates the pulsewidth of pulse-width modulation output control signal, makes output voltage values in the scope that the dc bus of inverter input stage allows.The purpose of sampling and outputting voltage value is whether the magnitude of voltage of the theory output that comparison controller calculates and the actual magnitude of voltage of exporting have difference, if difference is arranged, then can adjust accordingly again, in addition, the purpose of sampling input current is to calculate the input power value, by control output input stage circuit, make the battery etc. of Input voltage terminal be operated in the peak power output state.
Described the first switching tube Q1 and second switch pipe Q2 are parallel with respectively a diode, and the negative electrode of diode links to each other with the input of its switching tube in parallel, and the anode of diode links to each other with the output of its paralleling switch pipe; The effect of this diode is, when input voltage is excessive, and the reverse breakdown of diode own, thus protect the first switching tube Q1 and second switch pipe Q2 to avoid damaging the useful life of improving whole input stage circuit.
And the model selection pin of mode selection switch K2 is linked to each other with the input voltage negative pole, pattern 1 pin of mode selection switch K2 connects dc bus anode and the by-pass switch K1 of inverter input stage, the other end of by-pass switch K1 connects the positive pole of input voltage, pattern 2 pins of mode selection switch K2 connect the dc bus negative terminal of inverter input stage, and the control end of by-pass switch K1 and mode selection switch K2 links to each other with the controlling of sampling module.The purpose of this structure setting is, when the size of input voltage value is in the voltage range that the dc bus of inverter input stage allows, can be closed by controlling of sampling module controls by-pass switch K1, mode selection switch K2 connection mode 2 pins, like this, input voltage directly outputs to the dc bus of inverter input stage through bypass, reduce the input stage circuit power loss, improves inverter input stage conversion efficiency.
In addition, be in the purpose of the positive and negative inter-stage of an input voltage capacitor C 1 in parallel, for overcoming reduction voltage circuit or the discontinuous problem of booster circuit input current, add that before input stage circuit this circuit can play the effect of level and smooth and filtering to input voltage.
Present embodiment is further perfect to embodiment one, by the version of parallel diode, further improves the useful life of input stage circuit, shunt capacitance before input stage circuit, the effect of the smothing filtering that can get up to the voltage of input.
Embodiment three:
As shown in Figure 5, the inverter input stage circuit structural representation of the described wide range input voltage of the embodiment of the invention, details are as follows:
The inverter input stage circuit of the described wide range input voltage of present embodiment, comprise the first switching tube Q1, second switch pipe Q2, the 3rd switching tube Q3 and the 4th switching tube Q4, the second inductance L 2, the first inductance L 1, the controlling of sampling module, by-pass switch K1, mode selection switch K2, filter capacitor C1, output capacitance C2, the 3rd switching tube Q3 and the 4th switching tube Q4 and the second inductance L 2, the input of described the first switching tube Q1 links to each other with input voltage is anodal, the output of the first switching tube connects the first inductance L 1 and second switch pipe Q2, the output of second switch pipe links to each other with the dc bus negative terminal of inverter input stage, the other end of the first inductance L 1 connects the negative pole of input voltage and the dc bus anode of inverter input stage, one end of the second inductance L 2 connects the dc bus anode of inverter input stage, the other end of the second inductance L 2 connects the output of the 3rd switching tube Q3 and the input of the 4th switching tube Q4, the input of the 3rd switching tube Q3 connects the positive pole of input voltage, the output of the 4th switching tube Q4 links to each other with the dc bus negative terminal of inverter input stage, at the first switching tube Q1, second switch pipe Q2, the 3rd switching tube Q3 and the 4th switching tube Q4 are parallel with respectively diode, the negative electrode of diode links to each other with the input of its switching tube in parallel, the anode of diode links to each other with the output of its paralleling switch pipe, the first switching tube Q1, second switch pipe Q2, the control end of the 3rd switching tube Q3 and the 4th switching tube Q4 links to each other with acquisition control module, the first switching tube Q1, second switch pipe Q2, the 3rd switching tube Q3 and the 4th switching tube Q4 alternately control its switching by the controlling of sampling module; The model selection pin of described mode selection switch K2 links to each other with the input voltage negative pole, pattern 1 pin of mode selection switch K2 connects dc bus anode and the by-pass switch K1 of inverter input stage, the other end of by-pass switch K1 connects the positive pole of input voltage, pattern 2 pins of mode selection switch K2 connect the dc bus negative terminal of inverter input stage, and the control end of by-pass switch K1 and mode selection switch K2 links to each other with the controlling of sampling module; It is anodal that the end of described filter capacitor C1 connects input voltage, and the other end connects the negative pole of input voltage, and output capacitance C2 connects the both positive and negative polarity of output.
Fig. 6 is the input stage circuit schematic diagram of inverter of the wide range input voltage of the corresponding staggered control of the embodiment of the invention, and whole staggered control cycle is T, comprises T1, T2, four parts of T3, T4, and its staggered control procedure is as follows:
As scheme shown in the A, at T1 in the time period, controlling of sampling module controls the first switching tube Q1, the 4th switching tube Q4 are closed at this moment, second switch pipe Q2 and the 3rd switching tube Q3 open, battery as input voltage charges to the first inductance L 1 by the first switching tube Q1, and the second inductance L 2 is passed through the 4th switching tube Q4 to load discharge.
As scheme shown in the B, at T2 in the time period, controlling of sampling module controls second switch pipe Q2, the 4th switching tube Q4 are closed at this moment, the first switching tube Q1 and the 3rd switching tube Q3 open, to load and output capacitance C2 discharge, discharge to load and output capacitance C2 by the 4th switching tube Q4 by the second inductance L 2 by the second switch pipe for the first inductance L 1.
As scheme shown in the C, at T3 in the time period, controlling of sampling module controls second switch pipe Q2, the 3rd switching tube Q3 are closed at this moment, the first switching tube Q1 and the 4th switching tube Q4 open, battery as input voltage charges to the second inductance L 2 by the 3rd switching tube Q3, and the first inductance L 1 is discharged to load and output capacitance by second switch pipe Q2.
As scheme shown in the D, at T4 in the time period, controlling of sampling module controls the first switching tube Q1, the 3rd switching tube Q3 are closed at this moment, second switch pipe Q2 and the 4th switching tube Q4 open, battery as input voltage charges, charges to the first inductance L 1 by the first switching tube to the second inductance L 2 by the 3rd switching tube Q3, and output capacitance is discharged to load.
By the staggered control to switching tube, regulate the shared ratio value of each time portion, can reach the purpose of adjusting output voltage.
In addition, in the present embodiment, when input voltage value is in the scope of the dc bus permission of inverter input stage, this moment, the controlling of sampling module made by-pass switch K1 closed, mode selection switch preference pattern 2, consist of the input stage bypass this moment, and input stage circuit efficient is improved.
Present embodiment is compared with embodiment two, and its difference is, ascending, descending volt circuit in parallel under the staggered control of controlling of sampling module, reduces the switching tube burden on original circuit base, improves the stability of output level.
Embodiment four:
Fig. 7 is the inverter circuit structural representation of wide range input voltage, and details are as follows:
The inverter of the described wide range input voltage of present embodiment, the dc bus module 61 and the inversion module 62 that comprise the inverter input stage, the dc bus module 61 of described inverter input stage links to each other with inversion module 62,64 also are connected with input stage circuit 63 between direct busbar modules 61 and input circuit, described input stage circuit 63 comprises: comprise the first switching tube Q1, second switch pipe Q2, the first inductance L 1, the controlling of sampling module, by-pass switch K1 and mode selection switch K2, the input of described the first switching tube Q1 links to each other with input voltage is anodal, the output of the first switching tube connects the first inductance L 1 and second switch pipe Q2, the output of second switch pipe links to each other with the dc bus negative terminal of inverter input stage, the other end of the first inductance L 1 connects the negative pole of input voltage and the dc bus anode of inverter input stage, the magnitude of voltage of described controlling of sampling module Gather and input circuit and respectively with the first switching tube Q1, the control end of second switch pipe Q2 links to each other and alternately controls its switching, the model selection pin of described mode selection switch K2 links to each other with the input voltage negative pole, pattern 1 pin of mode selection switch K2 connects dc bus anode and the by-pass switch K1 of inverter input stage, the other end of by-pass switch K1 connects the positive pole of input voltage, pattern 2 pins of mode selection switch K2 connect the dc bus negative terminal of inverter input stage, and the control end of by-pass switch K1 and mode selection switch K2 links to each other with the controlling of sampling module.
In dc bus 61 modules of inverter input stage, the dc bus and the Support Capacitor C that comprise the inverter input stage, in inversion module 62, inverter bridge in the inversion module that the embodiment of the invention adopts, comprise that the 5th switching tube Q5, the 6th switching tube Q6, the 7th switching tube Q7 and the 8th switching tube Q8 bridge-type connect, at the output of inversion module serial connection outputting inductance L3 and L4 and be connected to electrical network.
Certainly, this input stage circuit also can adopt enforcement two or implement three described connected modes, further improves the implementation result of whole inverter.
Inverter described in the present embodiment with respect to conventional inverter, has following remarkable result:
(1) efficient inverter of present embodiment is with respect to traditional inversion input circuit, owing to adopt the input stage circuit of buck and bypass, its input voltage range is wider;
(2) the DC bus-bar voltage grade of the inverter input stage of present embodiment can reduce, and does not need to obtain with a plurality of capacitances in series the dc bus withstand voltage of higher inverter input stage, thereby so that cost greatly reduce;
(3) added by-pass switch K1 in the present embodiment, mode selection switch K2, by-pass switch K1 and mode switch K2 cooperate when in the dc bus operating voltage range of battery operated voltage in the inverter input stage, and the bypass input level takes full advantage of by-pass switch and improved inverter efficiency;
(4) in the present embodiment, the DC bus-bar voltage of inverter input stage maintains in the very little voltage range, so that the life-span of the dc bus Support Capacitor C of inverter input stage improves greatly.
The described switching tube of the embodiment of the invention comprises triode and metal-oxide-semiconductor, IGBT etc., can be realized its open and close controlling efficiently by controller.
Embodiment five:
Fig. 8 is the schematic flow sheet of the described realization wide range input voltage of the embodiment of the invention, and details are as follows:
In step S801, the magnitude of voltage of described controlling of sampling module Gather and input circuit.
Concrete, the magnitude of voltage of controlling of sampling module Gather and input circuit can adopt the circuit structure of resistance series connection dividing potential drop to take a sample, magnitude of voltage according to divider resistance, can calculate the magnitude of voltage of input voltage, such as the resistance for two equivalences of connecting, double to it at the magnitude of voltage of obtaining intermediate point, namely obtain the magnitude of voltage of input voltage.
In step S802, the input voltage that the gathers voltage range with the dc bus permission of inverter input stage is compared.
Concrete, the dc bus of inverter input stage has the voltage range value of a permission, such as the 40KV-50KV scope, the input voltage value that the gathers voltage range with the dc bus permission of this inverter input stage is compared, comparative result is divided into three kinds of situations, be respectively: the magnitude of voltage of collection greater than the magnitude of voltage of the maximum of the voltage range that allows, collection less than the magnitude of voltage of the minimum value of the voltage range that allows, collection within the voltage range that allows, respectively step S303, S304, the S305 of corresponding back.
In step S803, when the input voltage that gathers was lower than the minimum voltage value of the voltage range that the dc bus of inverter input stage allows, the controlling of sampling module improved the dutyfactor value of the first switching tube Q1.
Concrete, size according to the input voltage value that gathers, can regulate accordingly the dutyfactor value of the first switching tube Q1, be 40KV-50KV such as the DC bus-bar voltage scope for the inverter input stage, and detecting input voltage is 30KV, then improve the duty ratio of the first switching tube, accordingly, the numerical value of duty ratio and the size of input voltage and change, duty ratio corresponding is 0.6 when being 30KV such as input voltage, when input voltage was 20KV, the duty ratio of corresponding the first switching tube was 0.7 etc.Make input voltage obtain a satisfactory output voltage through after boosting, certainly, the corresponding DC bus-bar voltage scope of duty ratio also has a duty cycle range value, the duty ratio of regulating gets final product in this scope, and comparatively preferred mode is that to make output voltage be the middle part value of the voltage range that allows of dc bus.
In step S804, when the input voltage that gathers was higher than the maximum voltage value of the voltage range that the dc bus of inverter input stage allows, the controlling of sampling module reduced the dutyfactor value of the first switching tube Q1.
S803 is corresponding with step, when the voltage range 40-50KV that input voltage allows greater than the dc bus of inverter input stage, can reduce the dutyfactor value of the first switching tube Q1, when being 80KV such as input voltage, corresponding duty ratio is set to 0.3, its settings also have a scope, and more excellent mode is for being adjusted to output voltage the median of the voltage range of permission.
In step S805, when the input voltage that gathers is in the voltage range of the dc bus permission of inverter input stage, controlling of sampling module controls by-pass switch K1 conducting, mode selection switch K2 switches to bypass mode.
In the case, input voltage directly can be exported to the dc bus of inverter input stage by bypass, can reduce the loss that brings because of switching tube, improve inversion efficiency.
Certainly, for the circuit described in the embodiment three, because it has adopted staggered control, therefore, when originally improving or reducing the duty ratio of the first switching tube Q1, the corresponding duty ratio that improves or reduce the first switching tube Q1 and the 3rd switching tube Q3 that is adjusted into does not repeat to give unnecessary details at this.
In addition, there are some researches show, the solar inverter of corresponding same power grade, the solar module of configuration equal-wattage, input form by assembly series connection high pressure more is conducive to improve the energy output of whole inversion system than the low pressure group of manying connection in series-parallel input form, therefore, adjusts the operating voltage of inverter, make nearly possible the inputting with the series connection form of input solar components, thereby improve the operating efficiency of inversion system and the energy output of solar cell.
The above only is preferred embodiment of the present invention, not in order to limiting the present invention, all any modifications of doing within the spirit and principles in the present invention, is equal to and replaces and improvement etc., all should be included within protection scope of the present invention.