Power supply based on three-phase inverter bridge circuit splits device and control method thereof mutually
Technical field
The invention belongs to the circuit design technique field, relate in particular to a kind of power supply and split device and control method thereof mutually based on three-phase inverter bridge circuit.
Background technology
For the intrasystem three-phase load of single phase power supply (as threephase motor), need to adopt power supply to split the phase technology to obtain three-phase alternating-current supply.Compare monophase machine, the efficient of three phase electric machine will exceed more than 10%, and reliable, vibration is little, noise is low, the life-span is long.Therefore, in distribution system, promote the use of the saving that three phase electric machine can be realized electric energy, create remarkable economic efficiency.
Present common power supply splits the phase mode and utilizes electronic power rectification and inversion transformation technique to realize that its circuit structure comprises a diode rectifier bridge, filter inductance, electric capacity of voltage regulation and a three-phase inverter bridge circuit as shown in Figure 1.As can be seen from Figure 1, power supply commonly used splits mutually that device uses electronic component more, the cost height, and volume is big, and easy care not.
Summary of the invention
The objective of the invention is to, provide a kind of power supply to split device and control method thereof mutually, reduce power supply commonly used and split volume, the element of device mutually, and reduce manufacturing cost based on three-phase inverter bridge circuit.
Technical scheme is, a kind of power supply based on three-phase inverter bridge circuit splits device mutually, and device comprises 1 three-phase inverter bridge circuit, 1 electric capacity and 3 reactors that inductance value is equal to it is characterized in that splitting mutually by described power supply;
Wherein, the DC side parallel of described electric capacity and three-phase inverter bridge circuit;
The three-phase alternating current output of described three-phase inverter bridge circuit 1 reactor of connecting respectively;
The three-phase alternating current output of the three-phase inverter bridge circuit of described series reactor inserts load;
Any two-phase ac output end in the three-phase alternating current output of the three-phase inverter bridge circuit of described series reactor links to each other with the input of single phase alternating current power supply;
Each phase brachium pontis of described three-phase inverter bridge circuit is by the full-controlled switch device of two series connection and form with these two antiparallel diodes of full-controlled switch device respectively.
Described full-controlled switch device is an insulated gate bipolar transistor IGBT.
Described full-controlled switch device is gate level turn-off thyristor GTO.
Described load is the three-phase balanced impedance or the three phase electric machine of Y-connection.
Described load is three-phase balanced impedance or the three phase electric machine that triangle connects.
A kind of power supply based on three-phase inverter bridge circuit splits the control method of device mutually, it is characterized in that described control method comprises:
Step 1: the mould value of computational load and the impedance angle of load;
Step 2: obtain the phase place of single phase alternating current power supply voltage and calculate the amplitude of single phase alternating current power supply voltage;
Step 3: the input power factor of setting single phase alternating current power supply;
Step 4: according to the input power factor of the single phase alternating current power supply of the amplitude of the phase place of the impedance angle of the mould value of load, load, single phase alternating current power supply voltage, single phase alternating current power supply voltage and setting, computations electric current;
Step 5: generate the PWM trigger impulse that control full-controlled switch device cut-offs according to instruction current.
The described concrete chain rate that stagnates that adopts of PWM trigger impulse of cut-offfing according to instruction current generation control full-controlled switch device is than the control method, and its process comprises:
Step 501: calculate the capacitance voltage reference value, and the error of the actual value of itself and capacitance voltage is carried out the proportional integral computing, obtain voltage regulation signal;
Step 502: with the error of the actual current of instruction current and three-phase inverter bridge circuit output, and voltage regulation signal sends into hysteresis comparator, generates the PWM trigger impulse that control full-controlled switch device cut-offs.
Described calculating capacitance voltage reference value is utilized formula
Wherein M is the modulation ratio of three-phase inverter bridge circuit, and M≤1; U
RefBe the capacitance voltage reference value, U
sBe the effective value of single phase alternating current power supply voltage, I is that power supply splits the current effective value of device output mutually, and L is the inductance value of reactor; W is the angular frequency of single phase alternating current power supply voltage.
Power supply provided by the invention splits mutually that device has reduced electric component, and volume is littler; The single phase alternating current power supply output power factor can be regulated arbitrarily, has reduced network loss.
Description of drawings
Fig. 1 is that traditional power supply splits phase device circuit structure chart;
Fig. 2 is that the power supply based on three-phase inverter bridge circuit provided by the invention splits phase device circuit structure chart;
Fig. 3 is that the power supply based on three-phase inverter bridge circuit provided by the invention splits the control method schematic diagram of device mutually.
Embodiment
Below in conjunction with accompanying drawing, preferred embodiment is elaborated.Should be emphasized that following explanation only is exemplary, rather than in order to limit the scope of the invention and to use.
Fig. 2 is that the power supply based on three-phase inverter bridge circuit provided by the invention splits phase device circuit structure chart, among Fig. 2, the power supply based on three-phase inverter bridge circuit provided by the invention splits device mutually and comprises 1 three-phase inverter bridge circuit, 1 electric capacity and 3 reactors that inductance value equates.
Wherein, electric capacity and three-phase inverter bridge circuit DC side parallel.The three-phase alternating current output of three-phase inverter bridge circuit 1 the equivalent reactance device of connecting respectively; The three-phase alternating current output of three-phase inverter bridge circuit inserts load behind the series reactor respectively.The load that inserts can be the three-phase balanced impedance or the three phase electric machine of Y-connection, also can be three-phase balanced impedance or three phase electric machine that triangle connects.
Any two-phase ac output end of having connected in the three-phase alternating current output of three-phase inverter bridge circuit of equivalent reactance device links to each other with the input of single phase alternating current power supply.
Each phase brachium pontis of three-phase inverter bridge circuit is by the full-controlled switch device of two series connection and form with these two antiparallel diodes of full-controlled switch device respectively.The full-controlled switch device can be an insulated gate bipolar transistor IGBT, also can be gate level turn-off thyristor GTO.
Fig. 3 is that the power supply based on the three-phase bridge inverter circuit provided by the invention splits the control method schematic diagram of device mutually.In the present embodiment, be connected to example with the A cross streams output of three-phase inverter bridge circuit and C cross streams output and single phase alternating current power supply input, illustrate and utilize the power supply based on three-phase inverter bridge circuit provided by the invention to split device mutually, single phase alternating current power supply is converted to the control method of three-phase alternating-current supply.The specific implementation process of this control method is:
Step 1: according to known threephase load Z, the mould value of computational load | the impedance angle of Z| and load
Step 2: undertaken phase-lockedly by voltage waveform, obtain the phase place wt of single phase alternating current power supply voltage, and calculate the amplitude U of single phase alternating current power supply voltage to single phase alternating current power supply
s
Step 3: the input power factor θ that sets single phase alternating current power supply.
Step 4: according to the mould value of load | the impedance angle of Z|, load
The amplitude U of the phase place wt of single phase alternating current power supply voltage, single phase alternating current power supply voltage
sWith the input power factor θ of the single phase alternating current power supply of setting, computations current i
Ref
Be connected to example with the A cross streams output of three-phase inverter bridge circuit and C cross streams output and single phase alternating current power supply input, the current reference value of the three-phase output end output of three-phase inverter bridge circuit is respectively:
Above-mentioned current reference value is instruction current i
Ref
Step 5: generate the PWM trigger impulse that control full-controlled switch device cut-offs according to instruction current.
The method that generates the PWM trigger impulse that control full-controlled switch device cut-offs according to instruction current can adopt the chain rate that stagnates than control method or triangular carrier control method.In the present embodiment, chain rate is the process that example illustrates the PWM trigger impulse that cut-offs according to instruction current generation control full-controlled switch device than the control method to stagnate.This process is specifically:
Step 501: calculate the capacitance voltage reference value, and the error of the actual value of itself and capacitance voltage is carried out the proportional integral computing, obtain voltage regulation signal.
The capacitance voltage reference value is utilized formula
Calculate.Wherein, M is the modulation ratio of three-phase inverter bridge circuit, and M≤1; U
RefBe the capacitance voltage reference value, U
sBe the effective value of single phase alternating current power supply voltage, I is that power supply splits the current effective value of device output mutually, and L is the inductance value of equivalent reactance device; W is the angular frequency of single phase alternating current power supply voltage.
Step 502: with the error of the actual current of instruction current and three-phase inverter bridge circuit output, and voltage regulation signal sends into hysteresis comparator, generates the PWM trigger impulse that control full-controlled switch device cut-offs.
The PWM trigger impulse that the control full-controlled switch device of above-mentioned generation cut-offs is applied to the full-controlled switch device of three-phase inverter bridge circuit, can make power supply provided by the invention split the three-phase voltage and the three-phase current of device output symmetry mutually.
Power supply provided by the invention splits mutually device and control method thereof, only needs a three-phase inverter bridge circuit can finish power source conversion, compares the tradition that rectification adds inversion and splits the phase mode, rectifier bridge and DC filtering inductance have been saved, volume is littler, and cost is lower, and conversion efficiency is higher.In addition, the single phase alternating current power supply output power factor of device provided by the invention can be regulated arbitrarily, can improve the power factor of electrical network in actual applications, reduces network loss.
The above; only for the preferable embodiment of the present invention, but protection scope of the present invention is not limited thereto, and anyly is familiar with those skilled in the art in the technical scope that the present invention discloses; the variation that can expect easily or replacement all should be encompassed within protection scope of the present invention.Therefore, protection scope of the present invention should be as the criterion with the protection range of claim.