A kind of Active Power Filter-APF
Technical field
The utility model belongs to mains by harmonics processing unit field, is specifically related to a kind of Active Power Filter-APF.
Background technology
The appearance of harmonic current and harmonic voltage, is a kind of " pollution " for power system operation, and they have reduced the sine-shaped quality of system voltage, not only seriously affect electric power system self, but also jeopardizes user and communication system around; Since nearly half a century, along with applying of power electronic equipment, increase sharply (such as the application of electric locomotive, industrial furnace etc.) of nonlinear-load, the particularly utilization of high voltage direct current transmission, harmonic pollution problem is on the rise, and is therefore subject to the general concern of people and attention; The technical measures of harmonic reduction impact can be started with from two aspects: the one, from harmonic source, reduce the generation of harmonic wave; The 2nd, filter is installed; Common filter comprises passive filter, active filter and compound filter.Passive filter, also referred to as LC filter, is by the appropriately combined filter forming of filtering capacitor, reactor and resistor; Design of Passive Power Filter method is reliable and stable, simple in structure, but its filter effect depends on system impedance characteristics, and be easily subject to temperature drift, harmonic pollution degree on network, filter capacitor is aging and the impact of nonlinear-load; In addition, passive filter only can be decayed effectively to specific harmonic wave, and for the consideration of economy and floor space aspect, number of filter is all limited, so to the abundant occasion of harmonic content, the filter effect of passive filter is often not ideal enough; Corresponding with passive filter is active filter; Active Power Filter-APF adopts switch converters harmonic carcellation electric current, has overcome the short of electricity of passive filter; Active Power Filter-APF has the unrivaled technical advantage of passive filter, therefore more and more receives people's concern; But existing active filter is desirable not enough to the processing of idle compensation and three-phase current unbalance.
Summary of the invention
(1) technical problem that will solve
For addressing the above problem, the utility model proposes and a kind ofly can compensate reactive power, regulate three-phase current to make the Active Power Filter-APF of its balance.
(2) technical scheme
Active Power Filter-APF of the present utility model, comprises electrical network; Described electrical network is electrically connected to load place by current collecting device; Described current collecting device is electrically connected to controller by signal processing circuit; Described controller is electrically connected to the inverter circuit being comprised of symmetrical bipolar transistor by IGBT drive circuit; Described inverter circuit two ends are also connected to inductance capacitance branch road and inductive branch; Described inverter circuit forms loop by direct current PT; Described inverter circuit output is by being inductively coupled in electrical network.
Further, described inductance capacitance is composed in series after propping up three groups of electric capacity of route and inductance in parallel.
Further, on described inductive branch, be provided with switching device.
Further, described electrical network input is provided with plug-in strip and fuse.
Further, described signal processing circuit is electrically connected to form successively by amplifying circuit, filter circuit, shaping circuit and analog to digital conversion circuit.
(3) beneficial effect
Compared with prior art, it has following beneficial effect to the utility model: Active Power Filter-APF of the present utility model can compensate reactive power by inductance capacitance branch road and inductive branch; Cooperation by controller and inductance can regulate three-phase current to make the Active Power Filter-APF of its balance effectively in addition.
Accompanying drawing explanation
Fig. 1 is overall system diagram of the present utility model.
Embodiment
As shown in Figure 1, Active Power Filter-APF of the present utility model, comprises electrical network 1; Described electrical network 1 is electrically connected to load 2 places by current collecting device 3; Described current collecting device 3 is electrically connected to controller 5 by signal processing circuit 4; Described control 5 devices are electrically connected to the inverter circuit 7 being comprised of symmetrical bipolar transistor by IGBT drive circuit 6; Described inverter circuit 7 two ends are also connected to inductance capacitance branch road 8 and inductive branch 9; Described inverter 6 circuit form loop 10 by direct current PT; Described inverter circuit 7 outputs are coupled in electrical network by inductance 11.
Wherein, described inductance capacitance branch road 8 is composed in series after by three groups of electric capacity and inductance in parallel; On described inductive branch 9, be provided with switching device; Described electrical network 1 input is provided with plug-in strip and fuse; Described signal processing circuit 4 is electrically connected to form successively by amplifying circuit, filter circuit, shaping circuit and analog to digital conversion circuit.
Active Power Filter-APF of the present utility model can compensate reactive power by inductance capacitance branch road and inductive branch; Cooperation by controller and inductance can regulate three-phase current to make the Active Power Filter-APF of its balance effectively in addition.
Embodiment recited above is described preferred implementation of the present utility model, not design of the present utility model and scope is limited.Do not departing under the prerequisite of the utility model design concept; various modification and improvement that this area ordinary person makes the technical solution of the utility model; all should drop into protection range of the present utility model; the technology contents that the utility model is asked for protection, is all documented in claims.