CN104953801A - Harmonic current suppression device and method for voltage source grid-connected inverter - Google Patents

Abstract

The invention provides a harmonic current suppression device and method for a voltage source grid-connected inverter. The harmonic current suppression device comprises a grid-side sampler used for sampling grid-side voltage to acquire a grid-side voltage sampling signal, a first inverter sampler used for sampling output voltage and output current of an inverter to acquire an inverter voltage sampling signal and an inverter current sampling signal, a grid-side voltage processor used for separating N harmonic components from a fundamental component of the grid-side voltage sampling signal, a phase-locked loop used for detecting the amplitude and the phase position of the fundamental component, a power control loop used for calculating the amplitude regulating variable and the phase position regulating variable, a reference signal synthesizer used for generating an inverter voltage reference signal and an inverter control loop used for controlling the inverter to enable the output voltage to follow the inverter voltage reference signal. According to the harmonic current suppression device and method for the voltage source grid-connected inverter, harmonic current transmitted from the voltage source grid-connected inverter to the power grid can be effectively suppressed.

Description

Voltage-source type combining inverter current harmonics elimination device and method

Technical field

The present invention relates to technical field of inverter control, particularly, relate to a kind of voltage-source type combining inverter current harmonics elimination device and method.

Background technology

In recent years, along with the fossil fuels such as traditional coal and oil exhaust day by day, energy shortage and environmental problem are constantly aggravated, and make clean energy resource or renewable energy power generation technology obtain increasingly extensive attention and application.Greatly developing new and renewable sources of energy, be not only the needs of preserving the ecological environment, tackling climate change, realizing sustainable development, is also solve the main path of China remote districts without electric population people electrical problem.

For photovoltaic, its principal mode generated electricity by way of merging two or more grid systems is that to utilize take power electronic device as the inverter of core, and the DC conversion produced by photovoltaic battery panel is the alternating current form that electrical network can accept, and electric energy is injected electrical network.According to inverter output end characteristic, current source type combining inverter and voltage-source type combining inverter can be divided into.Wherein, the development of current source type combining inverter comparatively early, and range of application is wider, its operation principle is: inverter control loop only controls the output current of inverter, the output voltage of inverter carries out clamper by electrical network, current controlled circuit carries out maximal power tracing to photovoltaic battery panel simultaneously, and photovoltaic energy is injected electrical network to greatest extent.Because solar irradiance exists larger randomness, therefore grid-connected system output-power fluctuation is comparatively large, is unfavorable for the stabilization of power grids.The advantage of this system controls simply, and inverter output current waveform is better, input current total harmonic distortion (THD _i) lower.But its shortcoming is when the grid collapses, current source type grid-connected inverter system cannot realize islet operation and power for sensitive load.Voltage-source type grid-connected inverter system occurs more late, and its operation principle is amplitude by the output voltage of control inverter and phase place, and according to power transfer theorem, control inverter is to the active power of electrical grid transmission and reactive power.The feature of voltage-source type grid-connected inverter system is inverter control loop outermost layer is voltage control, and therefore, when electrical grid failure, voltage-source type grid-connected inverter system can off-grid immediately, and continues as sensitive load and provide electric energy.Due to voltage-source type grid-connected inverter system grid-connected with off-grid transfer process, the structure of its control loop does not change, transient process is impacted less, and the quality of power supply is higher, and therefore voltage-source type combining inverter can be promoted to the reliability that sensitive load is powered.But because the output impedance of voltage-source type combining inverter is less, be vulnerable to side harmonics voltage influence, therefore cause its grid-connected current THD _iincrease, the grid-connected current quality of power supply is impacted.

Therefore, need to provide a kind of voltage-source type combining inverter current harmonics elimination strategy, to solve the above-mentioned problems in the prior art at least in part.

Summary of the invention

In order to solve problems of the prior art at least in part, according to an aspect of the present invention, a kind of voltage-source type combining inverter current harmonics elimination device is provided.This device comprises: net side sampler, and it obtains voltage on line side sampled signal for sampling voltage on line side; First inverter sampler, it is for sampling to obtain contravarianter voltage sampled signal and inverter current sampled signal to the output voltage of inverter and output current; Voltage on line side processor, it is for being separated N number of harmonic component of voltage on line side sampled signal with fundamental component, wherein N be more than or equal to 1 integer; Phase-locked loop, it is for detecting the amplitude E of fundamental component _baseand phase theta _base; Power control loop, it is for calculating amplitude regulated quantity Δ E and phase adjusted amount Δ θ based on contravarianter voltage sampled signal, inverter current sampled signal, target active power and target reactive power; Reference signal synthesizer, it is for based on amplitude E _base, phase theta _base, amplitude regulated quantity Δ E, phase adjusted amount Δ θ and N number of harmonic component generate contravarianter voltage reference signal; And inverter control loop, it follows contravarianter voltage reference signal for control inverter to make output voltage.

Alternatively, voltage on line side processor comprises N group trapper and subtracter.This N group trapper is used for filtering N number of harmonic component correspondingly, and to obtain fundamental component, the angular frequency wherein often organizing the center resonance angular frequency of each trapper in trapper and the harmonic component corresponding with this group trapper is identical.This subtracter is used for from voltage on line side sampled signal, deducting fundamental component, to obtain N number of harmonic component.

Alternatively, this device comprises compensator further.This compensator is used for transfer function calculating based on each trapper in the angular frequency of fundamental component and N group trapper for compensating the amplitude compensation amount E of N group trapper on the impact that fundamental component causes _offsetwith phase compensation amount θ _offset, and be further used for respectively based on amplitude compensation amount E _offsetwith phase compensation amount θ _offsetto amplitude E _baseand phase theta _basecompensate.

Alternatively, the trapper for the harmonic component of filtering homophase voltage on line side in N group trapper is connected in series.

Alternatively, this device comprises a Clark and Park conversion module further, its for by Clark and Park conversion contravarianter voltage sampled signal and inverter current sampled signal are transformed to dq coordinate system under, with obtain through conversion contravarianter voltage sampled signal and through conversion inverter current sampled signal.Power control loop comprises power computation module and power control module.This power computation module comprises: power calculator, and it is for calculating the instantaneous active power that exports of inverter and instantaneous reactive power according to the contravarianter voltage sampled signal through conversion and the inverter current sampled signal through conversion; First low pass filter, it is for filtering the high fdrequency component in instantaneous active power, to obtain average active power; And second low pass filter, it is for filtering the high fdrequency component in instantaneous reactive power, to obtain average reactive power.This power control module comprises: the first subtracter, and it is for calculating the active power difference between target active power and average active power; Second subtracter, it is for calculating the reactive power difference between target reactive power and average reactive power; First proportional-integral-differential (PID) controller, it is for calculating phase adjusted amount Δ θ based on active power difference; And second PID controller, it is for calculating amplitude regulated quantity Δ E based on reactive power difference.

Alternatively, reference signal synthesizer specifically for: by amplitude regulated quantity Δ E and phase adjusted amount Δ θ respectively with amplitude E _baseand phase theta _basecombine to generate inverter fundamental frequency reference signal and by inverter fundamental frequency reference signal superimposed to generate contravarianter voltage reference signal with N number of harmonic component.

Alternatively, reference signal synthesizer generates inverter fundamental frequency reference signal based on formula below

$\left\{\begin{array}{c}{u}_{base\_a}^{*}=\left(\mathrm{\Δ}E+E_{base}\right)\sin \left(\mathrm{\Δ}\mathrm{\θ}+{\mathrm{\θ}}_{base}\right)\\ u_{base\_b}^{*}=\left(\mathrm{\Δ}E+E_{base}\right)\sin \left(\mathrm{\Δ}\mathrm{\θ}+{\mathrm{\θ}}_{base}-\frac{2\mathrm{\π}}{3}\right)\\ u_{base\_c}^{*}=\left(\mathrm{\Δ}E+E_{base}\right)\sin \left(\mathrm{\Δ}\mathrm{\θ}+{\mathrm{\θ}}_{base}+\frac{2\mathrm{\π}}{3}\right)\end{array}\right.,$

Wherein, with inverter fundamental frequency reference signal respectively component on abc three-phase.

Alternatively, this device comprises the second inverter sampler further, it is for sampling to the inductive current flowing through inductance or the capacitance current that flows through electric capacity, to obtain inductive current or capacitance current sampled signal, the wherein filter of inductance and electric capacity composition inverter, the high fdrequency component in the voltage that filter exports for the three phase full bridge circuit filtering head sea device.Inverter control loop comprises: the 2nd Clark and Park conversion module, it is under transforming to dq coordinate system by Clark and Park conversion by contravarianter voltage sampled signal and inductive current or capacitance current sampled signal, to obtain the contravarianter voltage sampled signal through conversion and the inductive current through conversion or capacitance current sampled signal; 3rd Clark and Park conversion module, its for by Clark and Park conversion contravarianter voltage reference signal is transformed to dq coordinate system under, with obtain through conversion contravarianter voltage reference signal; Voltage subtraction device, it is for calculating through the contravarianter voltage reference signal of conversion and the voltage difference between the contravarianter voltage sampled signal of conversion; Proportional, integral-resonance mixing (PIR) controller, it is for based on voltage difference calculating current ring reference signal; Current subtractor, it is for the current differential between calculating current ring reference signal and the inductive current through converting or capacitance current sampled signal; Current controller, it is for based on current differential calculating voltage modulation signal; Anti-Park and anti-Clark conversion module, its for by anti-Park and anti-Clark conversion voltage modulation signal is transformed to abc coordinate system under, with obtain through conversion voltage modulation signal; And modulator, it is for comparing the voltage modulation signal through converting and carrier signal, to obtain pulse-width signal, and utilize the device for power switching in the three phase full bridge circuit of pulse-width signal driving inverter, to make output voltage identical with contravarianter voltage reference signal.

Alternatively, the proportional, integral-transfer function of resonance mixture control under dq coordinate system is:

$G_{dqv}\left(s\right)=k_{pv}+\frac{k_{iv}}{s}+\underset{n}{\Σ}\frac{k_{rv\_n}s}{s^2+{\mathrm{\ω}}_{n}s+{(n\·{\mathrm{\ω}}_{base})}^2},$

Wherein, s is Laplacian, ω _basefor the angular frequency of described fundamental component, k _pvwith k _ivbe respectively scale parameter and integral parameter, k _{rv_n}with ω _nfor resonant controller parameter, and n=6k, wherein k is positive integer.

According to a further aspect in the invention, a kind of voltage-source type combining inverter method for inhibiting harmonic current is provided.The method comprises: sample to obtain voltage on line side sampled signal to voltage on line side; N number of harmonic component of voltage on line side sampled signal is separated with fundamental component, wherein N be more than or equal to 1 integer; Detect amplitude and the phase place of fundamental component; Sample to obtain contravarianter voltage sampled signal and inverter current sampled signal to the output voltage of inverter and output current; Amplitude regulated quantity and phase adjusted amount is calculated based on contravarianter voltage sampled signal, inverter current sampled signal, target active power and target reactive power; Contravarianter voltage reference signal is generated based on amplitude, phase place, amplitude regulated quantity, phase adjusted amount and N number of harmonic component; And control inverter follows contravarianter voltage reference signal to make output voltage.

According to technical scheme provided by the invention, fundamental component in the output voltage of inverter and the phase place between the fundamental component of voltage on line side and difference in magnitude are subject to the control of power control loop, the meritorious and reactive current (power) of the fundamental frequency therefore can specified to electrical grid transmission; Simultaneously, the error between the harmonic component in the output voltage of inverter and the harmonic component in voltage on line side can be reduced, therefore voltage-source type combining inverter effectively can be suppressed to the content of the harmonic current of electrical grid transmission, greatly reduce complexity and the design difficulty of grid-connected inverter system.

In summary of the invention, introduce the concept of a series of simplification, these concepts will further describe in embodiment part.Content part of the present invention does not also mean that the key feature and essential features that will attempt to limit technical scheme required for protection, does not more mean that the protection range attempting to determine technical scheme required for protection.

Below in conjunction with accompanying drawing, describe advantages and features of the invention in detail.

Accompanying drawing explanation

Following accompanying drawing of the present invention in this as a part of the present invention for understanding the present invention.Shown in the drawings of embodiments of the present invention and description thereof, be used for explaining principle of the present invention.In the accompanying drawings,

Fig. 1 a and 1b is respectively one phase equivalent circuit figure and the vector relations figure thereof of voltage-source type grid-connected inverter system;

Fig. 2 a and 2b is respectively single-phase fundamental component equivalent circuit diagram and the harmonic component equivalent circuit diagram of voltage-source type grid-connected inverter system;

Fig. 3 is the schematic block diagram of voltage-source type combining inverter current harmonics elimination device according to an embodiment of the invention;

Fig. 4 is the schematic block diagram of voltage-source type grid-connected inverter system according to an embodiment of the invention;

Fig. 5 is amplitude-frequency characteristic and the phase-frequency characteristic figure of trapper according to an embodiment of the invention;

Fig. 6 be according to an embodiment of the invention, the output voltage of voltage-source type combining inverter and output current be tied to the conversion schematic diagram of dq coordinate system from abc coordinate;

Fig. 7 is the flow chart of voltage-source type combining inverter method for inhibiting harmonic current according to an embodiment of the invention.

Embodiment

In the following description, a large amount of details is provided the present invention can be understood up hill and dale.But those skilled in the art can understand, following description only relates to preferred embodiment of the present invention, and the present invention can be implemented without the need to one or more such details.In addition, in order to avoid obscuring with the present invention, technical characteristics more well known in the art are not described.

Below in conjunction with Fig. 1 a, Fig. 1 b, Fig. 2 a and Fig. 2 b, the voltage-source type combining inverter current harmonics elimination principle according to the embodiment of the present invention is described.In the following description, " inverter ", " voltage-source type combining inverter " refer to identical object, and they can use interchangeably.

Get and analyze mutually with any in the voltage-source type grid-connected inverter system of three-phase equilibrium electrical network parallel running, its equivalent circuit diagram can be obtained, as shown in Figure 1a.V in figure _invfor voltage-source type combining inverter output voltage vector, V _gridfor voltage on line side vector, I is grid-connected current vector, Z _line=sL _line+ R _linefor the output of voltage-source type combining inverter and the substitutional connection impedance also between site.According to circuit theory, relation in Fig. 1 a between each vector can be represented with vector relations figure, as shown in Figure 1 b.According to Fig. 1 b, the active-power P of voltage-source type combining inverter to electrical grid transmission and the expression formula of reactive power Q can be obtained, be shown below:

$\left\{\begin{array}{c}P=\frac{V_{inv}^2}{Z}\cos \left(\mathrm{\θ}\right)-\frac{V_{inv}{V}_{grid}}{Z}\cos \left(\mathrm{\Δ}\mathrm{\φ}-\mathrm{\θ}\right)\\ Q=\frac{V_{inv}^2}{Z}\sin \left(\mathrm{\θ}\right)-\frac{V_{inv}{V}_{grid}}{Z}\sin \left(\mathrm{\Δ}\mathrm{\φ}-\mathrm{\θ}\right)\end{array}\right.---\left(1\right)$

In formula (1), Δ φ is vectorial V _invwith vectorial V _gridphase difference; Z and θ is substitutional connection impedance Z _lineamplitude and phase place.In the application scenario of voltage-source type combining inverter, line impedance mainly in perception, i.e. θ=pi/2, and Δ φ is very little in course of normal operation, that is: sin Δ φ ≈ Δ φ and cos Δ φ ≈ 1.Therefore, formula (1) can be reduced to formula (2):

$\left\{\begin{array}{c}P=\frac{V_{inv}{V}_{grid}}{{\mathrm{\ωL}}_{line}}\mathrm{\Δ}\mathrm{\φ}\\ Q=\frac{V_{inv}(V_{inv}-V_{grid})}{{\mathrm{\ωL}}_{line}}\end{array}\right.---\left(2\right)$

From formula (2), by the output voltage of control voltage source type interconnected inverter and and difference in magnitude (V between the voltage on line side at site place _inv-V _grid) with phase difference φ, can control inverter to the active-power P of electrical grid transmission and reactive power Q.When only there is fundamental component in voltage on line side, can utilize phase-locked loop to and the voltage on line side at site place detect, obtain instantaneous phase θ and the amplitude E of voltage on line side.Then utilize two proportional, integral (PI) controllers as power controller, respectively based on active power reference value (the i.e. target active power) P of inverter ^*and the difference between the actual active-power P exported of inverter, and the reactive power reference qref of inverter (i.e. target reactive power) Q ^*and the difference between the actual reactive power Q exported of inverter carries out computing, thus obtain phase adjusted amount Δ θ and the amplitude regulated quantity Δ E of the output voltage of inverter.Finally, utilize formula (3) synthesis contravarianter voltage reference signal below, and utilize the output voltage of contravarianter voltage current inner loop to inverter to control, make it follow contravarianter voltage reference signal thus make the principle of inverter according to formula (2), the active power of specifying to electrical grid transmission and reactive power.

$\left\{\begin{array}{c}{u}_a^{*}=\left(\mathrm{\Δ}E+E\right)\sin \left(\mathrm{\Δ}\mathrm{\θ}+\mathrm{\θ}\right)\\ u_b^{*}=\left(\mathrm{\Δ}E+E\right)\sin \left(\mathrm{\Δ}\mathrm{\θ}+\mathrm{\θ}-\frac{2\mathrm{\π}}{3}\right)\\ u_c^{*}=\left(\mathrm{\Δ}E+E\right)\sin \left(\mathrm{\Δ}\mathrm{\θ}+\mathrm{\θ}+\frac{2\mathrm{\π}}{3}\right)\end{array}\right.---\left(3\right)$

Be ω when voltage on line side exists angular frequency _harthe disturbance of three-phase equilibrium harmonic voltage time, according to linear superposition theorem, fundamental component equivalent circuit diagram and the angular frequency that Fig. 1 a can be decomposed into voltage-source type grid-connected inverter system are ω _harharmonic component equivalent circuit diagram, respectively as shown in Fig. 2 a and Fig. 2 b.U in figure _{ref_b}g _inv(j ω _base) and u _{ref_h}g _inv(j ω _har) be respectively the fundamental component of the output voltage of voltage-source type combining inverter and angular frequency is ω _harharmonic component; u _grid(j ω _base) and u _grid(j ω _har) be respectively the fundamental component of voltage on line side and angular frequency is ω _harharmonic component; Z _line(j ω _base) and Z _line(j ω _har) be respectively the fundamental component of substitutional connection impedance and angular frequency is ω _harharmonic component.I (j ω _base) and I (j ω _har) be respectively the fundamental component of grid-connected current and angular frequency is ω _harharmonic component.

According to Fig. 2 a, the fundamental component amplitude expression of any phase grid-connected current in voltage-source type grid-connected inverter system can be obtained, as follows:

$\left|I\left({\mathrm{j\ω}}_{base}\right)\right|=\left|\frac{u_{ref\_b}{G}_{inv}\left({\mathrm{j\ω}}_{base}\right)-u_{grid}\left({\mathrm{j\ω}}_{base}\right)}{Z_{line}\left({\mathrm{j\ω}}_{base}\right)}\right|---\left(4\right)$

According to Fig. 2 b, the harmonic component amplitude expression of any phase grid-connected current in voltage-source type grid-connected inverter system can be obtained, as follows:

$\left|I\left({\mathrm{j\ω}}_{har}\right)\right|=\left|\frac{u_{ref\_h}{G}_{inv}\left({\mathrm{j\ω}}_{har}\right)-u_{grid}\left({\mathrm{j\ω}}_{har}\right)}{Z_{line}\left({\mathrm{j\ω}}_{har}\right)}\right|---\left(5\right)$

As can be seen from formula (4), for ensureing when there is harmonic voltage disturbance in voltage on line side, voltage-source type combining inverter can normally be gained merit and reactive power to electrical grid transmission fundamental frequency, need based on formula (2), the fundamental component of the output voltage of voltage-source type combining inverter is carried out to the droop control of P/ θ and Q/E.As can be seen from formula (5), by reducing the mode of this formula Middle molecule absolute value, reduce the harmonic current identical with side harmonics voltage angle frequency that voltage-source type combining inverter exports.

Suppose that in voltage on line side, there is angular frequency is n ω _baseand peak value is b _nthree-phase equilibrium harmonic voltage, the expression formula of this harmonic voltage is as follows:

$\left\{\begin{array}{c}{u}_a=\underset{1}{\overset{\mathrm{\∞}}{\Σ}}{b}_{n}sin\[n\left({\mathrm{\ω}}_{base}t\right)\]\\ u_b=\underset{1}{\overset{\mathrm{\∞}}{\Σ}}{b}_{n}sin\[n\left({\mathrm{\ω}}_{base}t\right)-\frac{2}{3}\mathrm{\π}\]\\ u_c=\underset{1}{\overset{\mathrm{\∞}}{\Σ}}{b}_{n}sin\[n\left({\mathrm{\ω}}_{base}t\right)+\frac{2}{3}\mathrm{\π}\]\end{array}\right.---\left(6\right)$

Formula (6) can be converted through Clark and the Park transformation for mula shown in formula (7) below Yu formula (8):

$\left[\begin{array}{c}{x}_{\mathrm{\α}}\\ x_{\mathrm{\β}}\end{array}\right]=\left[\begin{array}{ccc}1& -1/2& -1/2\\ 0& \sqrt{3}/2& -\sqrt{3}/2\end{array}\right]\left[\begin{array}{c}{x}_a\\ x_b\\ x_c\end{array}\right]---\left(7\right)$

$\left[\begin{array}{c}{x}_d\\ x_q\end{array}\right]=\left[\begin{array}{cc}cos\mathrm{\θ}& sin\mathrm{\θ}\\ -sin\mathrm{\θ}& \cos \mathrm{\θ}\end{array}\right]\left[\begin{array}{c}{x}_{\mathrm{\α}}\\ x_{\mathrm{\β}}\end{array}\right]---\left(8\right)$

Obtain the expression formula of the three-phase equilibrium harmonic voltage under dq coordinate system thus, shown in (9):

$\left\{\begin{array}{c}{u}_d=\underset{n=1,4,7,10}{\overset{\mathrm{\∞}}{\Σ}}{b}_n\cos \left(n-1\right){\mathrm{\ω}}_{base}t-\underset{n=2,5,8,11}{\overset{\mathrm{\∞}}{\Σ}}{b}_n\cos \left(n+1\right){\mathrm{\ω}}_{base}t\\ u_q=\underset{n=4,7,10,13}{\overset{\mathrm{\∞}}{\Σ}}{b}_n\sin \left(n-1\right){\mathrm{\ω}}_{base}t-\underset{n=2,5,8,11}{\overset{\mathrm{\∞}}{\Σ}}{b}_n\sin \left(n+1\right){\mathrm{\ω}}_{base}t\end{array}\right.---\left(9\right)$

As can be seen from formula (9), the fundamental component of voltage on line side is mapped as the DC quantity on dq axle.And all harmonic components are all mapped as the trigonometric function signal on dq axle, and can not offset.According to the difference of former harmonic voltage signal positive sequence, negative phase-sequence, each harmonic component is mapped as the trigonometric function signal of different frequency on dq axle, wherein 1 time, 4 times, and 7 times are mapped as angular frequency on dq axle with 10 positive sequence harmonic components is (n-1) ω _basetrigonometric function signal; 2 times, 5 times, 8 times are mapped as angular frequency on dq axle with 11 Negative sequence harmonic components is (n+1) ω _basetrigonometric function signal.

It should be noted that, different according to side harmonics voltage angle frequency, can in the upper corresponding resonant controller in parallel of the Voltage loop controller (proportional-plus-integral controller) of voltage-source type combining inverter, form PIR controller, to improve the follow-up control of inverter control loop to net side three-phase equilibrium harmonic voltage, further elimination inverter output end and and site between harmonic voltage poor, contribute to realization reduce the harmonic current of voltage-source type combining inverter to electrical grid transmission by the molecule absolute value in reduction formula (5).

The present invention is further described below in conjunction with Fig. 3-7.

According to an aspect of the present invention, a kind of voltage-source type combining inverter current harmonics elimination is provided.Fig. 3 illustrates the schematic block diagram of voltage-source type combining inverter current harmonics elimination device 300 according to an embodiment of the invention.

Device 300 comprises net side sampler 301, first inverter sampler 302, voltage on line side processor 303, phase-locked loop 304, power control loop 305, reference signal synthesizer 306 and inverter control loop 307.

Wherein, net side sampler 301 and obtain voltage on line side sampled signal for sampling voltage on line side.First inverter sampler 302 is for sampling to obtain contravarianter voltage sampled signal and inverter current sampled signal to the output voltage of inverter and output current.Voltage on line side processor 303 for N number of harmonic component of voltage on line side sampled signal is separated with fundamental component, wherein N be more than or equal to 1 integer.Phase-locked loop 304 is for detecting the amplitude E of fundamental component _baseand phase theta _base.Power control loop 305 is for calculating amplitude regulated quantity Δ E and phase adjusted amount Δ θ based on contravarianter voltage sampled signal, inverter current sampled signal, target active power and target reactive power.Reference signal synthesizer 306 is for based on amplitude E _base, phase theta _base, amplitude regulated quantity Δ E, phase adjusted amount Δ θ and N number of harmonic component generate contravarianter voltage reference signal.Inverter control loop 307 follows contravarianter voltage reference signal for control inverter to make output voltage.

For the ease of understanding, describe the present invention in detail below in conjunction with Fig. 4.Fig. 4 is the schematic block diagram of voltage-source type grid-connected inverter system according to an embodiment of the invention.In the diagram, electrical network, voltage-source type combining inverter and voltage-source type combining inverter current harmonics elimination device associated with it is shown.One of ordinary skill in the art will appreciate that, be only an example realizing grid-connected inverter system of the present invention wherein shown in Fig. 4, for being expressly understood inventive concept of the present invention, but it is not construed as limiting the invention.

In the diagram, show voltage on line side processor 401, phase-locked loop 402, power control loop 403, reference signal synthesizer 404 and inverter control loop 405, they are corresponding with the voltage on line side processor 303 of Fig. 3, phase-locked loop 304, power control loop 305, reference signal synthesizer 306 and inverter control loop 307 respectively.

In the embodiment shown in fig. 4, net side sampler (not shown) to sample to obtain voltage on line side sampled signal u to voltage on line side _{grid_abc}.Voltage on line side processor 401 is by voltage on line side sampled signal u _{grid_abc}n number of harmonic component be separated with fundamental component, wherein N be more than or equal to 1 integer.

Alternatively, voltage on line side processor 401 can comprise N group trapper and subtracter.N group trapper is used for filtering N number of harmonic component correspondingly, to obtain fundamental component.The center resonance angular frequency of each trapper often in group trapper is identical with the angular frequency of the harmonic component corresponding with this group trapper.Subtracter is used for from voltage on line side sampled signal u _{grid_abc}in deduct fundamental component, to obtain N number of harmonic component.

Fig. 4 schematically illustrates use one group of trapper and subtracter carrys out separate mesh side voltage sampling signal u _{grid_abc}fundamental component and angular frequency be ω _harthe situation of harmonic component.As shown in Figure 4, voltage on line side processor 401 can also comprise demultiplexer (DEMUX), for by voltage on line side sampled signal u _{grid_abc}be separated on abc three-phase, obtain u _{grid_a}, u _{grid_b}and u _{grid_c}, then they are taken in independently of one another.In this case, one group of trapper comprise three identical, center resonance angular frequency _o=ω _hartrapper G _notch(s).Center resonance angular frequency is ω _othe transfer function of trapper such as formula shown in (10):

$G_{notch}\left(s\right)=\frac{s^2+ns+{\mathrm{\ω}}_0^2}{s^2+kns+{\mathrm{\ω}}_0^2}---\left(10\right)$

Trapper can be changed in center resonance angular frequency by k and the n value changed in formula (10) _othe neighbouring frequency of fadings width to signal and the degree of depth.Such as, as k=10 and time, center resonant frequency be the amplitude-frequency characteristic of the trapper of 550Hz and phase-frequency characteristic as shown in Figure 5.

Trapper G _notchs angular frequency can be ω by () _harharmonic component filtering, therefore, obtain the value u of fundamental component on abc three-phase respectively at the output of above-mentioned three trappers _{base_a}, u _{base_b}and u _{base_c}.As shown in Figure 4, voltage on line side processor 401 can also comprise the multiplexer (MUX) be connected with trapper, and it can by u _{base_a}, u _{base_b}and u _{base_c}synthesize fundamental component u _{base_abc}.Subtracter can by u _{grid_a}, u _{grid_b}, u _{grid_c}respectively with u _{base_a}, u _{base_b}and u _{base_c}subtract each other, to calculate angular frequency for ω _harthe value u of harmonic component on abc three-phase _{harmonic_a}, u _{harmonic_b}and u _{harmonic_c}.Voltage on line side processor 401 can also comprise the multiplexer be connected with subtracter, and it can by u _{harmonic_a}, u _{harmonic_b}and u _{harmonic_c}synthesize harmonic component u _{harmonic_abc}.

By voltage on line side sampled signal u _{grid_abc}in fundamental component express by formula (11) below with the process that harmonic component carries out being separated:

$\left\{\begin{array}{c}{u}_{base\_abc}=u_{grid\_abc}{G}_{notch}\left(s\right)\\ u_{harmonic\_abc}=u_{grid\_abc}-u_{base\_abc}\end{array}\right.---\left(11\right)$

Alternatively, the trapper for the harmonic component of filtering homophase voltage on line side in above-mentioned N group trapper is connected in series.When there is the harmonic voltage disturbance of multiple Frequency point in voltage on line side, utilize the many groups of structures having the trapper series connection of different center resonance angular frequency, can by the filtering one by one of the harmonic voltage of each Frequency point, and the structure shown in through type (12) is by voltage on line side sampled signal u _{grid_abc}in fundamental component be separated with harmonic component.

$\left\{\begin{array}{c}{u}_{base\_abc}=u_{grid\_abc}\underset{n=3,5,7,11}{\Π}{G}_{notch,n}\left(s\right)\\ u_{harmonic\_abc}=u_{grid\_abc}-u_{base\_abc}\end{array}\right.---\left(12\right)$

Alternatively, said apparatus may further include compensator (not shown).This compensator is used for transfer function calculating based on each trapper in the angular frequency of fundamental component and N group trapper for compensating the amplitude compensation amount E of N group trapper on the impact that fundamental component causes _offsetwith phase compensation amount θ _offset.This compensator is further used for respectively based on amplitude compensation amount E _offsetwith phase compensation amount θ _offsetto amplitude E _baseand phase theta _basecompensate.Be understandable that, when adopting above-mentioned trapper, trapper G _notchs () not only can by voltage on line side sampled signal u _{grid_abc}angular frequency be ω _harharmonic component filtering, also can to voltage on line side sampled signal u _{grid_abc}fundamental component have an impact.This impact is embodied in before the grid-connected switch of voltage-source type grid-connected inverter system is closed, needs the fundamental component of checking network side voltage sampling signal, and when the output voltage of inverter is carried out synchronous with the fundamental component of voltage on line side sampled signal.Trapper is compensated to the error that can reduce to produce in above-mentioned synchronizing process to the impact that fundamental frequency signal causes, grid-connected switch therefore can be avoided to close the impulse current of moment excessive, and then avoid damaging inverter.

Above-mentioned compensator calculates amplitude compensation amount E _offsetwith phase compensation amount θ _offsetprocess as follows.

First, by s=j ω _basebring trapper transfer function G into _notch(s), as follows:

$G_{notch}\left({\mathrm{j\ω}}_{base}\right)=\frac{({\mathrm{\ω}}_0^2-{{\mathrm{\ω}}_{base}}^2)+j\left({\mathrm{n\ω}}_{base}\right)}{({\mathrm{\ω}}_0^2-{{\mathrm{\ω}}_{base}}^2)+j\left({\mathrm{kn\ω}}_{base}\right)}---\left(13\right)$

ω in formula _basefor the angular frequency of the fundamental component of voltage on line side sampled signal.Then formula (13) is converted into the mould of plural number and the form at multiple angle, and carries out abbreviation, can obtain:

G _notch(jω _base)＝|g _notch|∠θ _notch(14)

In formula (14), $\left|g_{notch}\right|=\left|\frac{\left({\mathrm{\ω}}_0^2-{{\mathrm{\ω}}_{base}}^2\right)+j\left({\mathrm{n\ω}}_{base}\right)}{\left({\mathrm{\ω}}_0^2-{{\mathrm{\ω}}_{base}}^2\right)+j\left({\mathrm{kn\ω}}_{base}\right)}\right|,\∠{\mathrm{\θ}}_{notch}=\∠\[\frac{\left({\mathrm{\ω}}_0^2-{{\mathrm{\ω}}_{base}}^2\right)+j\left({\mathrm{n\ω}}_{base}\right)}{\left({\mathrm{\ω}}_0^2-{{\mathrm{\ω}}_{base}}^2\right)+j\left({\mathrm{kn\ω}}_{base}\right)}\].$

Therefore, the phase compensation amount θ of fundamental component can be obtained _offsetand amplitude compensation amount E _offset:

$\left\{\begin{array}{c}{\mathrm{\θ}}_{offset}=-\∠{\mathrm{\θ}}_{notch}\\ E_{offset}=1/\left|g_{notch}\right|\end{array}\right.---\left(15\right)$

When adopting many group trapper series connection, the phase compensation amount θ of fundamental component _offsetand amplitude compensation amount E _offsetbe shown below:

When calculating the amplitude compensation amount E of fundamental component _offsetwith phase compensation amount θ _offset, compensator can be utilized to compensate the amplitude of fundamental component and phase place.As described below, the amplitude of fundamental component and phase place can utilize phase-locked loop 402 to detect.

Phase-locked loop 402 is for detecting the amplitude E of fundamental component _baseand phase theta _base.Utilize the fundamental component u that phase-locked loop 402 pairs of voltage on line side processors 401 export _{base_abc}carry out computing, to obtain fundamental component u _{base_abc}phase theta _basewith amplitude E _base.Carry out computing by formula (17) below, the fundamental component u of trapper impact can be subject to _{base_abc}phase theta _basewith amplitude E _basevalue:

$\left\{\begin{array}{c}{\mathrm{\θ}}_{base}^{\′}={\mathrm{\θ}}_{base}+{\mathrm{\θ}}_{offset}\\ E_{base}^{\′}=E_{base}\×E_{offset}\end{array}\right.---\left(17\right)$

In formula (17), θ ' _basewith E ' _baserepresent the phase theta through compensating respectively _basewith the amplitude E through compensating _base.Although for convenience, employ different symbols to represent in formula (17) compensate before and after phase place and amplitude, be appreciated that perform compensate embodiment in, θ ' _basewith E ' _basebe the phase theta being input to follow-up reference signal synthesizer 404 _basewith amplitude E _base.

Continue with reference to figure 4, the first inverter sampler samples to obtain contravarianter voltage sampled signal u to the output voltage of inverter and output current _cabcwith inverter current sampled signal i _oabc.Power control loop 403 is based on contravarianter voltage sampled signal u _cabc, inverter current sampled signal i _oabc, target active-power P ^*with target reactive power Q ^*calculate amplitude regulated quantity Δ E and phase adjusted amount Δ θ.

Alternatively, said apparatus may further include a Clark and Park conversion module 406, and it is for passing through contravarianter voltage sampled signal u such as formula Clark and the Park conversion shown in (7) and formula (8) _cabcwith inverter current sampled signal i _oabcunder transforming to dq coordinate system, to obtain the contravarianter voltage sampled signal u through conversion _cdqwith the inverter current sampled signal i through conversion _odq, as shown in Figure 6.

Power control loop 403 can comprise power computation module 4031 and power control module 4032.Power computation module 4031 can comprise power calculator, for according to through conversion contravarianter voltage sampled signal u _cdqwith the inverter current sampled signal i through conversion _odqthe instantaneous active power P that calculating inverter exports and instantaneous reactive power Q.In this power calculation link, utilize instantaneous power theorem, calculate voltage-source type combining inverter to the instantaneous active power P of electrical grid transmission and instantaneous reactive power Q, be shown below:

$\left\{\begin{array}{c}P=u_{Cd}{i}_{Od}+u_{Cq}{i}_{Oq}\\ Q=u_{Cd}{i}_{Oq}-u_{Cq}{i}_{Od}\end{array}\right.---\left(18\right)$

Power computation module 4031 can also comprise the first low pass filter G _lPF(s) and the second low pass filter G _lPF(s), be respectively used to filter the high fdrequency component in instantaneous active power P and instantaneous reactive power Q, to obtain average active power p and average reactive power q, formula is as follows:

$\left\{\begin{array}{c}p=G_{LPF}\left(s\right)P\\ q=G_{LPF}\left(s\right)Q\end{array}\right.---\left(19\right)$

Power control module 4032 can comprise the first subtracter, the second subtracter, the first proportional-integral-differential (PID) controller and the second PID controller.First subtracter is for calculating target active-power P ^*and the active power difference between average active power p, the first PID controller is used for calculating phase adjusted amount Δ θ based on this active power difference, and this phase adjusted amount Δ θ is the phase adjusted amount of the output voltage for inverter.In like manner, the second subtracter is for calculating target reactive power Q ^*and the reactive power difference between average reactive power q.Second PID controller is used for calculating amplitude regulated quantity Δ E based on this reactive power difference, and this amplitude regulated quantity Δ E is the amplitude regulated quantity of the output voltage for inverter.Above-mentioned computational process is such as formula shown in (20):

$\left\{\begin{array}{c}\mathrm{\Δ}\mathrm{\θ}=k_{pp}(P^{*}-p)+k_{pi}\∫\left(P^{*}-p\right)dt+k_{pd}\frac{d}{dt}\left(P^{*}-p\right)\\ \mathrm{\Δ}E=k_{qp}(Q^{*}-q)+k_{qi}\∫\left(Q^{*}-q\right)dt+k_{qd}\frac{d}{dt}\left(Q^{*}-q\right)\end{array}\right.---\left(20\right)$

In formula (20), k _pp, k _pi, k _pdbe respectively the ratio of the first PID controller, integration and differential parameter; k _qp, k _qi, k _qdbe respectively the ratio of the second PID controller, integration and differential parameter.

Continue with reference to figure 4, reference signal synthesizer 404 is for based on amplitude E _base, phase theta _base, amplitude regulated quantity Δ E, phase adjusted amount Δ θ and N number of harmonic component generate contravarianter voltage reference signal

Alternatively, the reference signal synthesizer 404 amplitude regulated quantity Δ E that power control loop 403 can be exported and phase adjusted amount Δ θ export with phase-locked loop 402 respectively or through the amplitude E of overcompensation _baseand phase theta _basecombine to generate inverter fundamental frequency reference signal this calculating such as formula (21) trigonometric function relation shown in:

$\left\{\begin{array}{c}{u}_{base\_a}^{*}=\left(\mathrm{\Δ}E+E_{base}\right)\sin \left(\mathrm{\Δ}\mathrm{\θ}+{\mathrm{\θ}}_{base}\right)\\ u_{base\_b}^{*}=\left(\mathrm{\Δ}E+E_{base}\right)\sin \left(\mathrm{\Δ}\mathrm{\θ}+{\mathrm{\θ}}_{base}-\frac{2\mathrm{\π}}{3}\right)\\ u_{base\_c}^{*}=\left(\mathrm{\Δ}E+E_{base}\right)\sin \left(\mathrm{\Δ}\mathrm{\θ}+{\mathrm{\θ}}_{base}+\frac{2\mathrm{\π}}{3}\right)\end{array}\right.---\left(21\right)$

As shown in Figure 4, reference signal synthesizer 404 can comprise adder and reference signal generator, and both can be adopted to realize above-mentioned generation inverter fundamental frequency reference signal computational process.In the diagram, the inverter fundamental frequency reference signal that exports of reference signal generator for its component on abc three-phase with

Reference signal synthesizer 404 can be further used for inverter fundamental frequency reference signal superimposed to generate contravarianter voltage reference signal with N number of harmonic component as shown in Figure 4, reference signal synthesizer 404 may further include demultiplexer, adder and multiplexer.The harmonic component u that voltage on line side processor 401 or compensator export by demultiplexer _{harmonic_abc}decompose on abc three-phase, obtain u _{harmonic_a}, u _{harmonic_b}and u _{harmonic_c}.Output at reference signal generator obtains by adder with respectively with u _{harmonic_a}, u _{harmonic_b}and u _{harmonic_c}superimposed, shown in (22), produce the contravarianter voltage reference signal of complete three-phase afterwards through multiplexer

$\left\{\begin{array}{c}{u}_a^{*}=u_{base\_a}^{*}+u_{harmonic\_a}\\ u_b^{*}=u_{base\_b}^{*}+u_{harmonic\_b}\\ u_c^{*}=u_{base\_c}^{*}+u_{harmonic\_c}\end{array}\right.---\left(22\right)$

Alternatively, said apparatus may further include the second inverter sampler (not shown), for sampling to the inductive current flowing through inductance 411 or the capacitance current that flows through electric capacity 412, to obtain inductive current sampled signal i _labcor capacitance current sampled signal i _cabc, wherein inductance 411 and electric capacity 412 form the filter of inverter 410, the high fdrequency component in the voltage that this filter exports for the three phase full bridge circuit 413 filtering head sea device 410.

Inverter control loop 405 can comprise the 2nd Clark and Park conversion module 4051, the 3rd Clark and Park conversion module 4052, voltage subtraction device 4053, PIR controller 4054, current subtractor 4055, current controller 4056, anti-Park and anti-Clark conversion module 4057 and modulator 4058.

2nd Clark and Park conversion module 4051 is for converting contravarianter voltage sampled signal u by Clark and Park _cabcwith inductive current sampled signal i _labcor capacitance current sampled signal i _cabcunder transforming to dq coordinate system, to obtain the contravarianter voltage sampled signal u through conversion _cdqwith the inductive current sampled signal i through conversion _ldqor capacitance current sampled signal i _cdq.3rd Clark and Park conversion module 4052 is for converting contravarianter voltage reference signal by Clark and Park under transforming to dq coordinate system, to obtain the contravarianter voltage reference signal through conversion

Voltage subtraction device 4053 is for calculating the contravarianter voltage reference signal through conversion with the contravarianter voltage sampled signal u through conversion _cdqbetween voltage difference e _dq.PIR controller 4054 is for based on this voltage difference e _dqcalculating current ring reference signal in the diagram, square 4054 shows the inside structure of PIR controller 4054.The transfer function of PIR controller under dq coordinate system is such as formula shown in (23):

$G_{dqv}\left(s\right)=k_{pv}+\frac{k_{iv}}{s}+\underset{n}{\Σ}\frac{k_{rv\_n}s}{s^2+{\mathrm{\ω}}_{n}s+{(n\·{\mathrm{\ω}}_{base})}^2}---\left(23\right)$

In formula (23), s is Laplacian, ω _basefor the angular frequency of above-mentioned fundamental component, k _pvwith k _ivbe respectively scale parameter and integral parameter, k _{rv_n}with ω _nfor resonant controller parameter, and n=6k, wherein k is positive integer, i.e. n=6,12,18

Proportional integral link in formula (23) can make inverter control loop 405 realize controlling the stable state indifference of DC component under dq coordinate system, that is: realizing diagonal frequencies under abc coordinate system is ω _basefundamental component stable state indifference control; And resonance link can make inverter control loop realization diagonal frequencies under dq coordinate system be n ω _basethe stable state indifference of trigonometric function signal control, namely to realize under abc coordinate system diagonal frequencies for (n+1) ω _basethree-phase equilibrium positive sequence harmonic component of voltage or angular frequency be (n-1) ω _basethe stable state no error following of three-phase equilibrium Negative sequence harmonic component of voltage.

Current subtractor 4055 is for calculating current ring reference signal with the inductive current sampled signal i through converting _ldqor capacitance current sampled signal i _cdqbetween current differential.Current controller 4056 is for based on this current differential calculating voltage modulation signal u _dq.Anti-Park and anti-Clark conversion module 4057 are for converting voltage modulation signal u by anti-Park and anti-Clark _dqunder transforming to abc coordinate system, to obtain the voltage modulation signal u through conversion _abc.Anti-Park and anti-Clark transformation for mula are such as formula shown in (24) and formula (25):

$\left[\begin{array}{c}{x}_{\mathrm{\α}}\\ x_{\mathrm{\β}}\end{array}\right]=\left[\begin{array}{cc}cos\mathrm{\θ}& -sin\mathrm{\θ}\\ sin\mathrm{\θ}& \cos \mathrm{\θ}\end{array}\right]\left[\begin{array}{c}{x}_d\\ x_q\end{array}\right]---\left(24\right)$

$\left[\begin{array}{c}{x}_a\\ x_b\\ x_c\end{array}\right]=\left[\begin{array}{cc}1& 0\\ -1/2& \sqrt{3}/2\\ -1/2& -\sqrt{3}/2\end{array}\right]\left[\begin{array}{c}{x}_{\mathrm{\α}}\\ x_{\mathrm{\β}}\end{array}\right]---\left(25\right)$

After the computing through anti-Park and anti-Clark conversion module 4057, obtain the modulation signal u needed for three phase full bridge circuit 413 of the inverter 410 under abc coordinate system _abc.Afterwards, by the modulation signal u through conversion _abcbe input in modulator 4058.Modulator 4058 for by through conversion voltage modulation signal u _abccompare with carrier signal, to obtain pulse-width modulation (PWM) signal, and utilize the device for power switching in the three phase full bridge circuit 413 of pwm signal driving inverter 410, to make output voltage u _cabcwith contravarianter voltage reference signal identical, that is, electric capacity 412 obtains and contravarianter voltage reference signal identical output voltage u _cabc.

Known from the above description, the fundamental component in the output voltage of inverter and there is phase place and difference in magnitude between the fundamental component of voltage on line side.According to voltage-source type combining inverter current harmonics elimination device provided by the invention, fundamental component in the output voltage of inverter and the phase place between the fundamental component of voltage on line side and difference in magnitude are subject to the control of power control loop, the meritorious and reactive current (power) of the fundamental frequency therefore can specified to electrical grid transmission according to the relative theory described in formula (2); Simultaneously, employing said apparatus can reduce the error between the harmonic component in the output voltage of inverter and the harmonic component in voltage on line side, relative theory according to formula (5), voltage-source type combining inverter effectively can be suppressed to the content of the harmonic current of electrical grid transmission, greatly reduce complexity and the design difficulty of grid-connected inverter system.

According to a further aspect in the invention, a kind of voltage-source type combining inverter method for inhibiting harmonic current is provided.Fig. 7 illustrates the flow chart of voltage-source type combining inverter method for inhibiting harmonic current 700 according to an embodiment of the invention.Method 700 comprises the following steps.

In step S701, sample to obtain voltage on line side sampled signal to voltage on line side.

In step S702, N number of harmonic component of voltage on line side sampled signal is separated with fundamental component, wherein N be more than or equal to 1 integer.

In step S703, detect amplitude and the phase place of fundamental component.

In step S704, sample to obtain contravarianter voltage sampled signal and inverter current sampled signal to the output voltage of inverter and output current.

In step S705, calculate amplitude regulated quantity and phase adjusted amount based on contravarianter voltage sampled signal, inverter current sampled signal, target active power and target reactive power.

In step S706, generate contravarianter voltage reference signal based on amplitude, phase place, amplitude regulated quantity, phase adjusted amount and N number of harmonic component.

In step S707, control inverter follows contravarianter voltage reference signal to make output voltage.

By reading the above description to voltage-source type combining inverter current harmonics elimination device, one of ordinary skill in the art will appreciate that the step of voltage-source type combining inverter method for inhibiting harmonic current, feature and advantage thereof, not repeating them here.

The present invention is illustrated by above-described embodiment, but should be understood that, above-described embodiment just for the object of illustrating and illustrate, and is not intended to the present invention to be limited in described scope of embodiments.In addition it will be appreciated by persons skilled in the art that the present invention is not limited to above-described embodiment, more kinds of variants and modifications can also be made according to instruction of the present invention, within these variants and modifications all drop on the present invention's scope required for protection.Protection scope of the present invention defined by the appended claims and equivalent scope thereof.

Claims (10)

1. a voltage-source type combining inverter current harmonics elimination device, comprising:

Net side sampler, it obtains voltage on line side sampled signal for sampling voltage on line side;

First inverter sampler, it is for sampling to obtain contravarianter voltage sampled signal and inverter current sampled signal to the output voltage of inverter and output current;

Voltage on line side processor, it is for being separated N number of harmonic component of described voltage on line side sampled signal with fundamental component, wherein N be more than or equal to 1 integer;

Phase-locked loop, it is for detecting the amplitude E of described fundamental component _baseand phase theta _base;

Power control loop, it is for calculating amplitude regulated quantity Δ E and phase adjusted amount Δ θ based on described contravarianter voltage sampled signal, described inverter current sampled signal, target active power and target reactive power;

Reference signal synthesizer, it is for based on described amplitude E _base, described phase theta _base, described amplitude regulated quantity Δ E, described phase adjusted amount Δ θ and described N number of harmonic component generate contravarianter voltage reference signal; And

Inverter control loop, it follows described contravarianter voltage reference signal for controlling described inverter to make described output voltage.

2. device as claimed in claim 1, it is characterized in that, described voltage on line side processor comprises:

N group trapper, it is for filtering described N number of harmonic component correspondingly, and to obtain described fundamental component, the angular frequency wherein often organizing the center resonance angular frequency of each trapper in trapper and the harmonic component corresponding with this group trapper is identical; And

Subtracter, it for deducting described fundamental component from described voltage on line side sampled signal, to obtain described N number of harmonic component.

3. device as claimed in claim 2, it is characterized in that, described device comprises compensator further, and described compensator is used for transfer function calculating based on each trapper in the angular frequency of described fundamental component and described N group trapper for compensating described N group trapper to the amplitude compensation amount E of the impact that described fundamental component causes _offsetwith phase compensation amount θ _offset, and be further used for respectively based on described amplitude compensation amount E _offsetwith described phase compensation amount θ _offsetto described amplitude E _basewith described phase theta _basecompensate.

4. device as claimed in claim 2, it is characterized in that, the trapper for the harmonic component of filtering homophase voltage on line side in described N group trapper is connected in series.

5. device as claimed in claim 1, is characterized in that,

Described device comprises a Clark and Park conversion module further, its for by Clark and Park conversion described contravarianter voltage sampled signal and described inverter current sampled signal are transformed to dq coordinate system under, with obtain through conversion contravarianter voltage sampled signal and through conversion inverter current sampled signal;

Described power control loop comprises:

Power computation module, it comprises:

Power calculator, it is for calculating according to the described contravarianter voltage sampled signal through conversion and the described inverter current sampled signal through conversion the instantaneous active power and instantaneous reactive power that described inverter exports;

First low pass filter, it is for filtering the high fdrequency component in described instantaneous active power, to obtain average active power; And

Second low pass filter, it is for filtering the high fdrequency component in described instantaneous reactive power, to obtain average reactive power; And

Power control module, it comprises:

First subtracter, it is for calculating the active power difference between described target active power and described average active power;

Second subtracter, it is for calculating the reactive power difference between described target reactive power and described average reactive power;

First proportional-integral derivative controller, it is for calculating described phase adjusted amount Δ θ based on described active power difference; And

Second proportional-integral derivative controller, it is for calculating described amplitude regulated quantity Δ E based on described reactive power difference.

6. device as claimed in claim 1, is characterized in that, described reference signal synthesizer specifically for:

By described amplitude regulated quantity Δ E and described phase adjusted amount Δ θ respectively with described amplitude E _basewith described phase theta _basecombine to generate inverter fundamental frequency reference signal and

By described inverter fundamental frequency reference signal superimposed to generate contravarianter voltage reference signal with described N number of harmonic component.

7. device as claimed in claim 6, it is characterized in that, described reference signal synthesizer generates described inverter fundamental frequency reference signal based on formula below

$\{\begin{array}{c}{u}_{base\_a}^{*}=\left(\mathrm{\Δ}E+E_{base}\right)\sin \left(\mathrm{\Δ}\mathrm{\θ}+{\mathrm{\θ}}_{base}\right)\\ u_{base\_b}^{*}=\left(\mathrm{\Δ}E+E_{base}\right)\sin \left(\mathrm{\Δ}\mathrm{\θ}+{\mathrm{\θ}}_{base}-\frac{2\mathrm{\π}}{3}\right)\\ u_{base\_c}^{*}=\left(\mathrm{\Δ}E+E_{base}\right)\sin \left(\mathrm{\Δ}\mathrm{\θ}+{\mathrm{\θ}}_{base}+\frac{2\mathrm{\π}}{3}\right)\end{array},$

Wherein, with described inverter fundamental frequency reference signal respectively component on abc three-phase.

8. device as claimed in claim 1, is characterized in that,

Described device comprises the second inverter sampler further, it is for sampling to the inductive current flowing through inductance or the capacitance current that flows through electric capacity, to obtain inductive current or capacitance current sampled signal, wherein said inductance and described electric capacity form the filter of described inverter, the high fdrequency component in the voltage that described filter exports for the three phase full bridge circuit filtering described head sea device;

Described inverter control loop comprises:

2nd Clark and Park conversion module, it is under transforming to dq coordinate system by Clark and Park conversion by described contravarianter voltage sampled signal and described inductive current or capacitance current sampled signal, to obtain the contravarianter voltage sampled signal through conversion and the inductive current through conversion or capacitance current sampled signal;

3rd Clark and Park conversion module, its for by Clark and Park conversion described contravarianter voltage reference signal is transformed to dq coordinate system under, with obtain through conversion contravarianter voltage reference signal;

Voltage subtraction device, it is for calculating the described contravarianter voltage reference signal through conversion and described voltage difference between the contravarianter voltage sampled signal of conversion;

Proportional, integral-resonance mixture control, it is for based on described voltage difference calculating current ring reference signal;

Current subtractor, it is for calculating the current differential between described electric current loop reference signal and described inductive current through converting or capacitance current sampled signal;

Current controller, it is for based on described current differential calculating voltage modulation signal;

Anti-Park and anti-Clark conversion module, its for by anti-Park and anti-Clark conversion described voltage modulation signal is transformed to abc coordinate system under, with obtain through conversion voltage modulation signal; And

Modulator, it is for comparing the described voltage modulation signal through conversion and carrier signal, to obtain pulse-width signal, and utilize described pulse-width signal to drive device for power switching in the three phase full bridge circuit of described inverter, to make described output voltage identical with described contravarianter voltage reference signal.

9. device as claimed in claim 8, it is characterized in that, the described proportional, integral-transfer function of resonance mixture control under dq coordinate system is:

$G_{dqv}\left(s\right)=k_{pv}+\frac{k_{iv}}{s}+\underset{n}{\Σ}\frac{k_{rv\_n}s}{s^2+{\mathrm{\ω}}_{n}s+{(n\·{\mathrm{\ω}}_{base})}^2},$

Wherein, s is Laplacian, ω _basefor the angular frequency of described fundamental component, k _pvwith k _ivbe respectively scale parameter and integral parameter, k _{rv_n}with ω _nfor resonant controller parameter, and n=6k, wherein k is positive integer.

10. a voltage-source type combining inverter method for inhibiting harmonic current, comprising:

Sample to obtain voltage on line side sampled signal to voltage on line side;

N number of harmonic component of described voltage on line side sampled signal is separated with fundamental component, wherein N be more than or equal to 1 integer;

Detect amplitude and the phase place of described fundamental component;

Sample to obtain contravarianter voltage sampled signal and inverter current sampled signal to the output voltage of inverter and output current;

Amplitude regulated quantity and phase adjusted amount is calculated based on described contravarianter voltage sampled signal, described inverter current sampled signal, target active power and target reactive power;

Contravarianter voltage reference signal is generated based on described amplitude, described phase place, described amplitude regulated quantity, described phase adjusted amount and described N number of harmonic component; And

Control inverter follows described contravarianter voltage reference signal to make described output voltage.