The method that AC drive vehicle transless controls direct current outputTechnical field
The present invention relates to AC drive vehicle transless topological structure and the methods for controlling direct current output.
Background technology
Currently, drawing the structure of electric drive system on traditional high-power electric locomotive or EMU is：ContactNet-tractive transformer-rectifier-intermediate DC circuit-inverter-traction electric machine.Wherein, tractive transformer is heavy, makesHigh price is expensive, and occupies a large amount of space, the weight and manufacturing cost of locomotive has both been increased, also in train traction or regenerative brakingWhen, copper loss and iron loss are generated, utilization rate of electrical is made to reduce.In addition, transformer can also bring a series of problems, such as Wen Sheng, leakage reactance.
Invention content
In order to remove transformer, avoid the problem that transformer is brought, in order to allow each converting unit that there is stable direct currentOutput ensures voltage stabilization between each converting unit and does not influence each other that the present invention provides a kind of AC drive vehicles without changeDepressor topological structure and the method for controlling direct current output.
In order to achieve the above objectives, AC drive vehicle transless topological structure, including mutual cascade two or moreConverting unit；The converting unit includes controller, pulse rectifier, resistance and inductance, and controller receives the friendship of grid sideFlow voltage signal UacWith ac current signal Iac, while controller receives the d. c. voltage signal U of pulse rectifier output enddcWith DC current signal Idc, the output end of controller is connected with pulse rectifier, with DC voltage given value on controllerInput terminal；Controller is by DC voltage UdcWith DC voltage given valueIt is compared, the difference compared is input to controllerIn pi regulator in, pi regulator exports reference current IN1；As reference current IN1Increase, controller controls pulse rectifierInput current increase, to make the output current of pulse rectifier increase；As reference current IN1Reduce, controller controls pulseThe input current of rectifier reduces, to make the output current of pulse rectifier reduce；Above-mentioned control process repeatedly, allows direct currentPress UdcRelative to DC voltage given valueChange in given range；The output end of resistance is connect with grid side, resistance it is defeatedOutlet is connected by connecting with inductance with pulse rectifier.
AC drive vehicle transless control direct current output method be：Power grid to mutually cascade two or more turnUnit power supply is changed, each converting unit divides the voltage of power grid, and exchange is converted to direct current output by converting unit；SpecificallyProcess is：In each converting unit, power grid passes through the resistance R and capacitance L that are serially connectedNPulse rectifier is supplied electricity to, in arteries and veinsIt rushes alternating current in rectifier and is converted to direct current electricity output；Pulse rectifier passes through control in exchange is converted to direct current processDevice controls the direct current output of pulse rectifier, and specific process is：The alternating current of controller detection grid side in converting unitPress Uac, alternating current IacWith the DC voltage U of pulse rectifier output enddc, DC current Idc, while being inputted into controllerOne DC voltage given valueBy DC voltage UdcWith DC voltage given valueIt is compared, the difference compared is inputtedInto the pi regulator in controller, pi regulator exports reference current IN1；As reference current IN1Increase, controller controls arteries and veinsThe input current for rushing rectifier increases, to make the output current of pulse rectifier increase；As reference current IN1Reduce, controllerThe input current for controlling pulse rectifier reduces, to make the output current of pulse rectifier reduce；Above-mentioned control process repeatedly,Allow DC voltage UdcRelative to DC voltage given valueChange in given range.
The method of above topology structure and control direct current output, since voltage of multiple converting units to grid side is utilizedIt is divided, alternating current is converted into direct current using pulse rectifier, to eliminate transformer, it is stupid to solve transformerWeigh, involve great expense, occupying the technical issues of big quantity space, also solve in train traction or regenerative braking generate copper loss andThe technical issues of iron loss, makes utilization rate of electrical height.In addition, also solving transformer brings a series of technology such as Wen Sheng, leakage reactanceProblem.In the present invention, as a result of the comparative approach of controller, to ensure DC voltage UdcIt is given relative to DC voltageDefinite valueChange in given range, ensure voltage stabilization between each converting unit and do not influence each other, recited herein givesIt refers to the edge in ± U values to determine range, and U values are set as needed.
Further, the pulse rectifier is three level pulse rectifiers, wherein the poles A of three level pulse rectifiersIt is connect with the output end of inductance, the poles B of three level pulse rectifiers are connect with the poles A of adjacent converting unit, and three level pulses are wholeThe output end of the poles g and controller of flowing device connects.
Further, the first capacitance is provided between three level pulse rectifier output cathodes and the poles N, in three level arteries and veinsIt rushes between the cathode of rectifier and the poles N and plays balance due to being provided with the first capacitance and the second capacitance provided with the second capacitanceThe effect of voltage ensures N extremely 0 current potentials.
Further, AC voltage sensor is parallel on pulse rectifier, controller receives AC voltage sensorAc voltage signal；AC current sensor is in series between grid side and resistance, controller receives ac current sensorAc current signal on device.
Further, it is parallel with direct current voltage sensor in the output end of pulse rectifier, controller receives DC voltageThe d. c. voltage signal of sensor；It is in series with DC current sensor in the output end of pulse rectifier, controller receives direct currentThe DC current signal of current sensor.Due to being provided with AC voltage sensor, AC current sensor, DC voltage sensingTherefore device and DC current sensor easily and accurately obtain alternating voltage, alternating current, DC voltage and DC current.
Further, according toAnd UdcObtain IN1Method be：
Wherein, KpIn order to control in device pi regulator proportionality coefficient, TiThe time of integration of pi regulator is normal in device in order to controlNumber.
Further, voltage U is generated in the controllersSignal, by voltage UsThe waveform of signal is converted into pulse signal, leads toExtra pulse signal controls pulse rectifier, generates voltage UsThe process of signal is：
(1) in the controller, according to Idc、UdcAnd UNCalculate reference current value IN2；
IN2=IdcUdc/UN
Wherein, UNFor exchange side voltage effective value；
(2) in the controller, according to IN1And IN2Calculate IN1And IN2And value IN※
IN※=IN1+IN2
(3) in the controller, U is calculateds；
Wherein, R is resistance value, LNFor inductance value, ω is the angular frequency of grid side voltage, G2For rate mu-factor, iNForAc-side current virtual value.
On the other hand the above method, the signal that on the one hand can be identified in order to which pulse rectifier can be received pass throughAbove-mentioned calculating can be more accurately controlled signal.
Description of the drawings
Fig. 1 is the topology diagram of the present invention.
Fig. 2 is the oscillogram of pulse rectifier output.
Specific implementation mode
As shown in Figure 1, AC drive vehicle transless topological structure includes mutually cascade two or more conversion listsMember 100, the cascade refers to being divided using converting unit, and each converting unit all has output end.The conversionUnit 100 includes controller 1, pulse rectifier 2, resistance 3 and inductance 4.
Controller 1 has DC voltage given value input terminal, ac voltage signal input terminal, ac current signal inputEnd, d. c. voltage signal input terminal, DC current signal input terminal and output end p ulse.DC voltage given value input terminationReceive DC voltage given valueAc voltage signal input terminal receives the ac voltage signal U from AC voltage sensorac,Ac current signal input terminal receives the ac current signal I from AC current sensorac, d. c. voltage signal input terminationReceive the d. c. voltage signal U from direct current voltage sensordc, DC current signal input terminal, which receives, comes from DC current sensorDC current signal Idc, the poles the g connection of output end p ulse and pulse rectifier.
The pulse rectifier 2 is three level pulse rectifiers, wherein the poles A of three level pulse rectifiers and inductance 4Output end connection, the poles B of three level pulse rectifiers and the poles A of three level pulse rectifiers in adjacent converting unit connectIt connects, the poles g of three level pulse rectifiers are connect with the output end p ulse of controller 1.
The first capacitance 5 is provided between three level pulse rectifier output cathodes and the poles N, in three level pulse rectifiersCathode and the poles N between be provided with the second capacitance 6, play the role of balanced voltage, ensure N extremely 0 current potentials.
Resistance 3 and inductance 4 are sequentially connected in series, and the output end of resistance 3 is connected to the input terminal of inductance 4.The input terminal of resistance 3 with200 side of power grid connects.
It is parallel with alternating voltage between three poles level pulse rectifier B in grid side 200 and first converting unitSensor 7；The three level pulse poles rectifier B in second converting unit and three level pulses in first converting unit are wholeStream is parallel with AC voltage sensor between device B poles, the three level pulse poles rectifier B in third converting unit and secondBe parallel with AC voltage sensor between three poles level pulse rectifier B in converting unit, and so on until second from the bottomA converting unit is parallel with AC voltage sensor 7 between three poles level pulse rectifier B in the last one converting unit,The ac voltage signal input terminal of controller receives the ac voltage signal of AC voltage sensor 7.In 200 side of power grid and resistanceAC current sensor 8 is in series between 3, the ac current signal input terminal of controller receives on AC current sensor 8Ac current signal.It is parallel with direct current voltage sensor 9, the d. c. voltage signal of controller in the output end of pulse rectifier 2Input terminal receives the d. c. voltage signal of direct current voltage sensor 9；Direct current is in series in the output end of pulse rectifier to spreadSensor 10, the DC current signal input terminal of controller receive the DC current signal of DC current sensor 10.Pass through exchangeVoltage sensor 7, AC current sensor 8, direct current voltage sensor 9 and DC current sensor 10 can intuitively, it is accurateTo alternating voltage, alternating current, DC voltage and DC current.
In order to more intuitively obtain curent change the case where, be connected with first in the output end of AC current sensorDisplay screen 11 is connected with second display screen 12 on the output end of DC current sensor.
AC drive vehicle transless control direct current output method include：Power grid 200 to mutually cascade two withOn converting unit 100 power, each converting unit 100 divides the voltage of power grid, and converting unit 100 is converted to exchangeDirect current output；Specifically process is：In each converting unit 100, power grid 200 passes through the resistance R and capacitance L that are serially connectedNPulse rectifier 2 is supplied electricity to, alternating current is converted to direct current electricity output in pulse rectifier 2；Pulse rectifier 2 turns in exchangeIt is changed in direct current process, the direct current output of pulse rectifier 2 is controlled by controller 1, specific process is：In converting unitController 1 detects the alternating voltage U of 200 side of power gridac, alternating current IacWith the DC voltage U of pulse rectifier output enddc, it is straightGalvanic electricity stream Idc, while a DC voltage given value is inputted into controller 2By DC voltage UdcWith DC voltage given valueIt is compared, the difference compared is input in the pi regulator in controller, pi regulator exports reference current IN1, rootAccording toAnd UdcObtain IN1Method be：
Wherein, KpIn order to control in device pi regulator proportionality coefficient, TiThe time of integration of pi regulator is normal in device in order to controlNumber.
I is obtainedN1Generate voltage U in the controller afterwardssSignal, then by voltage UsThe waveform of signal is converted into pulse letterNumber, pulse rectifier 2 is controlled by pulse signal and is worked, voltage U is generatedsThe process of signal is：
(1) in the controller, according to Idc、UdcAnd UNCalculate reference current value IN2；
IN2=IdcUdc/UN
Wherein, UNFor exchange side voltage effective value；
(2) in the controller, according to IN1And IN2Calculate IN1And IN2And value IN※
IN※=IN1+IN2
(3) in the controller, U is calculateds；
Wherein, R is resistance value, LNFor inductance value, ω is the angular frequency of grid side voltage, G2For rate mu-factor, iNForAc-side current virtual value.
It is by the method that pulse signal controls pulse rectifier：As DC voltage UdcLess than DC voltage given valueReference current IN1Increase, USIt changes, pulse signal also follows variation, and pulse rectifier is controlled by the pulse signal of variationInput current increase, to make the output current of pulse rectifier increase；As DC voltage UdcMore than DC voltage given valueReference current IN1Reduce, USIt changes, pulse signal also follows variation, and it is whole to control pulse by the pulse signal of variationThe input current for flowing device reduces, to make the output current of pulse rectifier reduce；Above-mentioned control process repeatedly, allows DC voltageUdcRelative to DC voltage given valueChange in given range, i.e. DC voltage UdcIn DC voltage given valueOnLower fluctuation, realization are accurately controlled, and are allowed pulse rectifier to have and are stablized, accurately export, ensure voltage between each converting unitStablize and do not influence each other, as shown in Figure 2.Given range recited herein refers to the edge in ± U values, and U values are as neededSetting.
In the present invention, it in order to test the operating condition of the structure, can be connected on the output end of pulse rectifier 2 equivalentLoad 13.
In actual use, equivalent load 13 is canceled, inverter is connected in the output end of pulse rectifier 2,Motor is connected on inverter.
Topological structure using the present invention and method divide the voltage of 200 side of power grid using multiple converting units 100Pressure, direct current is converted to using pulse rectifier 2 by alternating current so that the output end of each converting unit has stable direct currentOutput solves transformer heaviness, involves great expense, occupies the technical issues of big quantity space, also solve to eliminate transformerThe technical issues of copper loss and iron loss are generated in train traction or regenerative braking, makes utilization rate of electrical height.In addition, also solvingTransformer brings a series of technical problem such as Wen Sheng, leakage reactance.