A kind of major loop and its control method for micro-grid system charge and discharge deviceTechnical field
The present invention relates to micro-capacitance sensor control field, in particular to a kind of major loop for micro-grid system charge and discharge deviceAnd its control method.
Background technique
Micro-capacitance sensor is the controllable energy supplying system being made of devices such as distributed energy, energy-storage units and loads.Due to micro-Power grid has been to be concerned by more and more people in advantages such as power supply reliability, safety, sustainabilities.With energy-storage battery groupMicro-grid system, on the one hand, when power grid energy supply is abundant, power grid energy is passed through into two-way DC/AC rectifier, two-way DC/DC converter, to energy-storage battery energy storage；On the other hand, when power grid energy supplies nervous, energy-storage battery energy can be passed through doubleTo DC/DC converter, two-way DC/AC rectifier to power grid feedback energy.
Micro-grid system with energy-storage battery can be to power grid in peak of power consumption and low ebb, according to load condition, spiritGround living regulation power flow direction.The energy conversion system being made of power electronic devices provides the two-way function of micro-capacitance sensor connection power gridRate channel, to ensure safety, reliability and the high efficiency of energy-storage battery charge and discharge.Current most of charge and discharge devices are twoA charge and discharge unidirectional device composition or a charge and discharge two-way device.The former cost, volume are larger, and the latter does not examineConsider the operation characteristic of power grid feed and battery charging.
Summary of the invention
The present invention relates to a kind of main circuits and its control method for micro-grid system charge and discharge device, in particular to rootIt is instructed according to charge and discharge, by switching high frequency transformer primary side contactor, to complete to be used for micro-grid system charge and discharge difference functionThe switching in rate path.
To solve the above problems, the technical scheme adopted by the invention is as follows:
A kind of major loop for micro-grid system charge and discharge device, comprising: sequentially connected grid interface, filter circuitModule, two-way DC/AC rectifier module, two-way DC/DC converter module and energy-storage battery group and control circuit and power directionControl module；
The two-way DC/DC converter module include exchange H bridge single-phase inverter circuit, power switch module andTransformer；Power switch module includes contactor KM1 and KM2, and exchange H bridge single-phase inverter circuit passes through contactor respectivelyThe connection of the primary and secondary side of KM1 and KM2 and transformer；
The control circuit and power direction control module acquires grid interface, filter circuit module, two-way DC/ respectivelyThe coherent signal of AC rectifier module, two-way DC/DC converter module and energy-storage battery group, and control two-way DC/AC rectifierThe switching of module, two-way DC/DC converter module and power switch module.
The exchange H bridge single-phase inverter circuit includes two branch being made of two power devices series connection in parallelRoad, two input terminals of contactor KM1 are separately connected between two power devices of each branch, two outputs of contactor KM1The both ends of end connection transformer primary winding, transformer primary winding side is provided with decoupling capacitor on one end；Transformer secondary aroundThe both ends of group connect filter inductance L by diode respectively, and filter inductance L is connect with energy-storage battery group anode, vice-side windingCentre cap connects energy-storage battery group cathode, the input terminal parallel filtering capacitor C of energy-storage battery group；One of contactor KM2 is defeatedEnter end connection exchange H bridge single-phase inverter circuit cathode, output end connects energy-storage battery group cathode；Contactor KM2's is anotherBetween a input terminal connection one branch, two power devices, output end connects the input terminal of filter inductance L.
The two-way DC/DC converter module includes channel isolation and non-isolated channel, and channel isolation is by power deviceT1D1、T2D2、T3D3And T4D4The exchange H bridge single-phase inverter circuit of composition, contactor KM1, decoupling capacitor, transformer, diodeThe full-wave rectifying circuit of composition, the DC filtering circuit of LC composition form；Non-isolated channel by filter inductance L, contactor KM2,Switch transistor T4, diode D2And the DC side filter capacitor composition of two-way DC/AC rectifier module.
A kind of control method of the major loop for micro-grid system charge and discharge device, comprising the following steps:
Control circuit and power direction control module are instructed according to charge and discharge judges power direction, to power switchThe contactor KM1 and contactor KM2 of module issue corresponding control signal, are contacted by switching in two-way DC/DC converter moduleDevice KM1 and KM2, to realize the switching in micro-grid system charge and discharge different capacity path.
As a further improvement of the present invention, the first power path is that electric energy successively passes through grid interface, filter circuit mouldBlock, two-way DC/AC rectifier module, two-way DC/DC converter module channel isolation and energy-storage battery group, power grid is to energy-storage batteryGroup charging, stores energy；Second power path be electric energy successively pass through energy-storage battery group, two-way DC/DC converter module it is non-everyFrom channel, two-way DC/AC rectifier module, filter circuit module and grid interface, energy-storage battery group discharges energy to power grid energy regenerativeAmount.
As a further improvement of the present invention, specific step is as follows for charging process:
1) after control circuit and power direction control module obtain upper charge command, to connecing for power switch moduleTentaculum KM1 issues Continuity signal, while issuing cut-off signals to contactor KM2；
2) according to the control program of the rectification mode of two-way DC/AC rectifier module, control circuit and power direction controlModule carries out coherent signal acquisition and control algolithm, carries out corresponding rectification mode control to two-way DC/AC rectifier module；
3) power flows through two-way DC/DC converter module and connects channel isolation, control circuit and power direction control moduleCarry out coherent signal acquisition and control algolithm, exchange H bridge single-phase inverter circuit controlled, electric energy through contactor KM1, goCoupling capacitor, transformer electromagnetic coupling rectified by vice-side winding and the full-wave rectifying circuit that diode is constituted, then pass throughThe DC filtering circuit of LC composition, charges to energy-storage battery group.
As a further improvement of the present invention, specific step is as follows for discharge process:
1) after control circuit and power direction control module obtain upper electric discharge order, to connecing for power switch moduleTentaculum KM1 issues cut-off signals, while issuing Continuity signal to contactor KM2；
2) power flows through the two-way non-isolated channel of DC/DC converter module, control circuit and function by energy-storage battery group electric energyRate direction controlling module completes coherent signal acquisition and control algolithm, to by filter inductance L, contactor KM2, switch transistor T4, twoPole pipe D2And the DC B oost boost chopper of the DC side filter capacitor composition of two-way DC/AC rectifier module carries outControl, transformer are out of service；
3) according to the control program of the inverter mode of two-way DC/AC rectifier module, control circuit and power direction controlModule completes coherent signal acquisition and control algolithm, carries out corresponding inverter mode control to two-way DC/AC rectifier module, willEnergy inversion completes energy-storage battery group discharge circuit function to power grid.
Compared with the existing technology, the invention has the following advantages:
Circuit structure of the invention passes through easy contactor by increasing contactor in two-way DC/DC converter moduleControl, makes two-way DC/DC converter have the two-way power channels in different capacity direction, and control circuit and power direction control mouldRoot tuber is instructed according to charge and discharge, by switching high frequency transformer primary side contactor, to complete for micro-grid system charge and discharge notWith the switching of power path.The configuration of the present invention is simple, circuit design are at low cost, small in size, effectively realize and fill to energy-storage batteryEnergy channel isolation is needed when electric, to reduce interference of the charging unit energy fluctuation to battery；And energy-storage battery discharges to power gridWhen need non-isolated access, to reach faster energy transmission real-time and higher energy transfer efficiency.
In control method of the invention, control circuit and power direction control module are instructed according to charge and discharge, pass through switchingHigh frequency transformer primary side contactor, to complete to be used for the switching in micro-grid system charge and discharge different capacity path.Realize micro- electricityNet system charge and discharge double-direction control, has the characteristics that safety, reliability and high efficiency.
Detailed description of the invention
Fig. 1 is the main circuit schematic diagram that the present invention is used for micro-grid system charge and discharge device；
Wherein: 1, grid interface；2, filter circuit module；3, two-way DC/AC rectifier module；4, two-way DC/DC transformationDevice module；5, energy-storage battery group；6, control circuit and power direction control module；7, power switch module.
When Fig. 2 is that energy-storage battery charges, the control principle drawing in two-way DC/DC inverter power path I；
Wherein, 4, two-way DC/DC converter module, 7, power switch module, bold portion are isolation power pathⅠ。
When Fig. 3 is that energy-storage battery discharges, the control principle drawing in two-way DC/DC inverter power path II；
Wherein, 4, two-way DC/DC converter module, 7, power switch module, bold portion are non-isolated power roadDiameter II.
Specific embodiment
With reference to the attached drawing in the embodiment of the present invention, technical solution in the embodiment of the present invention carries out clear, completeGround description.
As shown in Figure 1, a kind of main circuit for micro-grid system charge and discharge device, comprising: grid interface 1, filtered electricalRoad module 2, two-way DC/AC rectifier module 3, two-way DC/DC converter module 4, energy-storage battery group 5, control circuit and powerDirection controlling module 6 and power switch module 7, power switch module 7 are made of contactor KM1 and KM2.
Exchange H bridge single-phase inverter circuit includes two branches being made of two power devices series connection in parallel, contactTwo input terminals of device KM1 are separately connected between two power devices of each branch, and two output ends of contactor KM1, which connect, to be becomeThe both ends of depressor primary side, transformer primary avris are provided with decoupling capacitor on one end；The both ends of transformer secondary winding pass through respectivelyFirst diode, the second diode connect filter inductance L, and the centre cap of vice-side winding connects energy-storage battery group cathode, filteringInductance L is connect with 5 anode of energy-storage battery group, the input terminal parallel filtering capacitor C of energy-storage battery group 5；One of contactor KM1 is defeatedEnter end connection exchange H bridge single-phase inverter circuit cathode, output end connects 5 cathode of energy-storage battery group；Contactor KM1's is anotherBetween a input terminal connection one branch, two power devices, output end connects the input terminal of filter inductance L.
It specifically, include channel isolation and non-isolated channel in two-way 4 structure of DC/DC converter module.Channel isolationBy power device T1D1~T4D4The high-frequency ac H bridge single-phase inverter circuit of composition, contactor KM1, decoupling capacitor, high frequency becomeThe DC filtering circuit composition of full-wave rectifying circuit, LC composition that depressor, diode are constituted；Non-isolated channel by filter inductance L,Contactor KM2, switch transistor T4, diode D2And the DC side filter capacitor composition of two-way DC/AC rectifier module 3.
Main circuit of the invention mainly includes two power paths, when charging to energy-storage battery, contactor KM1 conducting,Contactor KM2 is disconnected, and constitutes I channel of power path；When energy-storage battery is fed to power grid, contactor KM1 is disconnected, contactorKM2 conducting, constitutes II channel of power path.Power path I is that electric energy successively passes through grid interface 1, filter circuit module 2, doubleTo DC/AC rectifier module 3, two-way 4 channel isolation of DC/DC converter module, energy-storage battery group 5, power grid is to energy-storage battery groupCharging stores energy；It is non-isolated that power path II is that electric energy successively passes through energy-storage battery group 5, two-way DC/DC converter module 4Channel, two-way DC/AC rectifier module 3, filter circuit module 2, grid interface 1, energy-storage battery group discharge energy to power grid energy regenerativeAmount.
Power path I and power path II are to judge power direction by control circuit and power direction control module 6, toThe contactor KM1 and contactor KM2 of power switch module 7 issue corresponding control signal, to reach two-way DC/DC converter4 switch in the path in I channel isolation of power path and the non-isolated channel of power path II.
After obtaining host computer charging signals for micro-grid system charge and discharge device, control circuit and power direction controlModule 6 issues Continuity signal to the contactor KM1 of power switch module 7, and contactor KM2 issues cut-off signals.Power grid energyAmount successively filters 2, the rectification of two-way DC/AC rectifier module 3, two-way DC/DC by grid interface 1, filter circuit moduleI channel of power path of converter module 4 is charged to energy-storage battery.I channel of power path of two-way DC/DC converter moduleAs above-mentioned, control is as shown in Figure 2.Control circuit and power direction control module 6 complete power path switching, and to main electricityRoad carries out power control.Its step are as follows:
1) control circuit and power direction control module 6, after obtaining upper charge command, to power switch module7 contactor KM1 issues Continuity signal, while issuing cut-off signals to contactor KM2；
2) according to the control program of the rectification mode of two-way DC/AC rectifier module 3, control circuit and power direction controlModule 6 completes coherent signal acquisition and control algolithm, carries out corresponding rectification mode control to two-way DC/AC rectifier module 3；
3) power flows through two-way 4 channel isolation of DC/DC converter module as above stated, control circuit and power direction controlModule 6 completes coherent signal acquisition and control method, to by power device T1D1~T4D4The high-frequency ac H bridge of composition is single-phase inverseBecome device circuit to be controlled, through contactor KM1, by decoupling capacitor, by the electromagnetic coupling of transformer by vice-side winding and twoThe full-wave rectifying circuit that pole pipe is constituted is rectified, and the DC filtering circuit being then made up of LC carries out energy-storage battery group 5Charging.
After obtaining host computer discharge signal for micro-grid system charge and discharge device, control circuit and power direction controlModule 6 issues cut-off signals to the contactor KM1 of power switch module 7, and contactor KM2 issues Continuity signal.Energy storage electricityPond energy successively pass through II channel of power path of two-way DC/DC converter module, two-way DC/AC rectifier module inversion,Filter circuit module filtering, by grid interface to power grid feedback energy.The power path II of two-way DC/DC converter moduleChannel control process is as follows, and control is as shown in Figure 3.After obtaining upper electric discharge order, control circuit and power direction control mouldBlock 6 switches when completing power path, and carries out power control to main circuit.Its step are as follows:
1) control circuit and power direction control module 6, after obtaining upper electric discharge order, to power switch module7 contactor KM1 issues cut-off signals, while issuing Continuity signal to contactor KM2；
2) power is flowed through by energy-storage battery group 2 such as the above-mentioned non-isolated channel of two-way DC/DC converter module 4, control electricityRoad and power direction control module 6 complete coherent signal acquisition and control method, to by filter inductance L, contactor KM2, switchPipe T4, diode D2And the DC B oost boost chopper electricity of the DC side filter capacitor composition of two-way DC/AC rectifier module 3Road is controlled, and high frequency transformer is out of service.
3) according to the control program of the inverter mode of two-way DC/AC rectifier module 3, control circuit and power direction controlModule 6 completes coherent signal acquisition and control algolithm, carries out corresponding inverter mode control to two-way DC/AC rectifier module 3.By energy inversion to power grid, 5 discharge circuit function of energy-storage battery group is completed.
The foregoing is only a preferred embodiment of the present invention, but scope of protection of the present invention is not limited thereto,Within the technical scope of the present disclosure, any changes or substitutions that can be easily thought of by anyone skilled in the art,It should be covered by the protection scope of the present invention.Therefore, protection scope of the present invention should be with the protection model of claimsSubject to enclosing.