Summary of the invention
For the deficiencies in the prior art, the invention provides a kind of Bidirectional up-down straightening current converter that is applied to energy-storage system, the present invention is elevated to the voltage range that the rear class inverter can work with the output voltage of the battery of the different electric pressures of variety classes.In order to cooperate the energy storage combining inverter, this converter has the power bi-directional function, when large capacity, with the use in parallel of the converter of many same models, to satisfy various network systems to the demand of power.
The objective of the invention is to adopt following technical proposals to realize:
A kind of Bidirectional up-down straightening current converter that is applied to energy-storage system, its improvements are that described Bidirectional up-down straightening current converter is included in the energy-storage system, and described Bidirectional up-down straightening current converter comprises input capacitance C
i, filter inductance L
m, transistor S
1, transistor S
2With output capacitance C
0The anode of energy-storage system connects input capacitance C
iPositive pole and filter inductance L
mOne end; Described filter inductance L
mThe other end connects transistor S
1Drain electrode and transistor S
2The common point of source electrode; Described transistor S
2Drain electrode connects output capacitance C
0Positive pole and the input side of energy storage combining inverter anodal; Described energy storage combining inverter input side negative pole connects output capacitance C
0Negative pole, transistor S
1Source electrode, input capacitance C
iNegative pole and battery cathode.
Wherein, described transistor S
1With transistor S
2Be the insulated gate bipolar transistor IGBT switching tube; Described IGBT switching tube is comprised of antiparallel diode and triode.
Wherein, described input capacitance C
iThe current ripples that is used for the output of filtering battery or input.
Wherein, described filter inductance L
mIn a switch periods, according to the on off state of IGBT switching tube, discharge electric energy after the first store electrical energy.
Wherein, when described bidirectional Buck-Boost converter is operated in the boost mode, described transistor S
1As switching tube, described transistor S
2Diode as fly-wheel diode; When described bidirectional Buck-Boost converter is operated in the decompression mode, described transistor S
1Diode as fly-wheel diode, described transistor S
2As switching tube.
Wherein, described boost mode is battery charging mode according to user; Described decompression mode is the battery discharge pattern.
Wherein, described output capacitance C
0Be used for the output of filtering inverter or input or current ripples.
Wherein, described energy-storage system comprises battery pack, at least two DC converter, energy storage combining inverter and electrical networks; Described battery pack is comprised of the battery of at least one; Described battery storing is in battery rack; Be connected with the energy storage combining inverter after DC converter of each battery series connection; In the described energy storage combining inverter access electrical network; At least two DC converter parallel connections.
Wherein, described DC converter or be Bidirectional up-down straightening current converter.
Wherein, the electric pressure of described battery pack input is between 300V~800V; The battery of described battery pack adopts lead-acid battery, all-vanadium flow battery, sodium-sulphur battery, lithium battery, fuel cell or super capacitor.
Compared with the prior art, the beneficial effect that reaches of the present invention is:
1, the Bidirectional up-down straightening current converter that is applied to energy-storage system provided by the invention, wide-range input voltage is applicable to different electric pressures between 300V~800V, the battery rack of different size.
2, the function that has energy in bidirectional flow.
3, in large-power occasions, can be with the use in parallel of many DC converter, to satisfy the demand of various operating modes.
4, applied widely: as can be widely used in photovoltaic market, extensive energy-storage system, microgrid and rural power grids, areas without electricity etc.
5, by increasing DC converter, can improve flexibility, the reliability and maintainability of whole system, reduce inverter system to the electric requirement of input distributed power source.
6, circuit topology adopts Interleaving and Transformer Paralleling, and in the battery side parallel connection a large electric capacity, therefore greatly reduced the battery current ripple, having reduced in charge and discharge process has increased the life-span of battery to a certain extent to the impact of battery.
7, battery can be various types of other batteries such as plumbic acid, all-vanadium flow, sodium-sulphur battery, lithium battery, can also replace applying flexible with fuel cell and super capacitor simultaneously.
Embodiment
Below in conjunction with accompanying drawing the specific embodiment of the present invention is described in further detail.
Energy-storage battery schematic diagram provided by the invention as shown in Figure 1, energy-storage system comprises battery pack, DC converter, energy storage combining inverter and electrical network; Described battery pack is comprised of the battery of at least one; Battery storing is in battery rack; With the use in parallel of many DC converter, every DC converter connects a battery rack, and the output with DC converter is parallel on the dc bus of energy storage combining inverter input together again; In the described energy storage combining inverter access electrical network.
The Bidirectional up-down straightening current converter circuit topology that is applied to energy-storage system provided by the invention as shown in Figure 2, Bidirectional up-down straightening current converter is included in the energy-storage system, described Bidirectional up-down straightening current converter comprises input capacitance C
i, filter inductance L
m, lower pipe S
1Insulated gate bipolar transistor (Insulated Gate Bipolar Transistor is called for short IGBT), upper pipe S
2Insulated gate bipolar transistor and output capacitance C
0Described anode connects input capacitance C
iPositive pole and filter inductance L
mOne end; Described filter inductance L
mThe other end connects lower pipe S
1Drain electrode and upper pipe S
2The common point of source electrode; Described upper pipe S
2Drain electrode connects output capacitance C
0Positive pole and the input side of energy storage combining inverter anodal; Energy storage combining inverter input side negative pole connects output capacitance C
0Negative pole, upper pipe S
1Source electrode, input capacitance C
iNegative pole and battery cathode.
Input capacitance C
i: filter action guarantees that the current ripples of battery output (input) meets the demands.Filter inductance L
m: in a switch periods, according to the on off state of IGBT switching tube, discharge electric energy after the first store electrical energy.Switching tube S
1And S
2: in boost mode, lower pipe S
1As switching tube, upper pipe S
2Body diode as fly-wheel diode.In decompression mode, lower pipe S
1As fly-wheel diode, upper pipe S
2Body diode as switching tube.Output capacitance C
O: filter action guarantees that the current ripples of inverter output (input) meets the demands.
When converter is operated under the boost mode, lower pipe S
1Insulated gate bipolar transistor (Insulated Gate Bipolar Transistor is called for short IGBT) is as the switching tube of booster circuit topological mode, pipe S in the utilization
2Body diode as the fly-wheel diode of booster circuit topological mode.Circuit-mode is lifted to voltage the voltage range that the inverter of rear class can work when battery discharge; Otherwise, under the mode of operation of battery charging, reverse direction current flow, this moment, circuit topology became BUCK reduction voltage circuit pattern, upper pipe S
2As switching tube, lower pipe S
1Body diode as the fly-wheel diode of BUCK reduction voltage circuit pattern, circuit is taked two-way Bidirectional variable-flow topology pattern in parallel, reducing the input and output current ripples, thereby reduces input filter capacitor appearance value and volume, as shown in Figure 2.
Should be noted that at last: above embodiment is only in order to illustrate that technical scheme of the present invention is not intended to limit, although with reference to above-described embodiment the present invention is had been described in detail, those of ordinary skill in the field are to be understood that: still can make amendment or be equal to replacement the specific embodiment of the present invention, and do not break away from any modification of spirit and scope of the invention or be equal to replacement, it all should be encompassed in the middle of the claim scope of the present invention.