CN105490297A - Microgrid supply voltage and grid current harmonics synchronous compensation method based on dual inverter group coordinated control - Google Patents

Abstract

The invention relates to a microgrid supply voltage and grid current harmonics synchronous compensation method based on dual inverter group coordinated control. The method is characterized in that a topological structure with dual interface converters connected in parallel; according to a dual-inverter voltage/current coordinated control strategy, a converter A is responsible for compensating harmonics of a supply voltage in real time, a converter B is responsible for compensating a harmonic current generated by a load and a converter 2, thus guaranteeing the quality of electric energy of current at a grid side. The control method is capable of omitting the extraction link of the harmonic current and a phase-locked loop, thus greatly lowering the calculation quantity of a digital control system; in addition, through the coordinated control of the two converters, the waveforms of the supply voltage and the grid current are improved and the quality of electric energy is enhanced obviously. Therefore, the control method plays an important role in reducing system loss and ensuring the safe and stable operation of the system.

Description

Based on micro-capacitance sensor supply power voltage and the grid current harmonic synchroballistic method of twin inverter group cooperation control

Technical field

The present invention relates to a kind of power grid quality administering method, particularly a kind of micro-capacitance sensor supply power voltage based on twin inverter group cooperation control and grid current harmonic synchroballistic method.

Background technology

Improve constantly along with the attention rate of user to power supply reliability and the quality of power supply and the various forms of regenerative resource such as solar energy, wind energy utilizes in a large number, micro-capacitance sensor obtains the extensive concern of Chinese scholars as the effective way of distributed power source access electrical network.Micro-capacitance sensor generally refers to the small grids form multiple distributed power source, energy storage device and load coupled together by power electronic equipment, can be incorporated into the power networks, with traditional bulk power grid positive energy exchange, again can independent operating, become the isolated system of an energy stable operation.

Along with a large amount of accesses of distributed generation unit, power quality problem is increasingly serious.The method improving the quality of power supply is generally adopt passive filter or active filter.Passive filter adopts with the appropriately combined filter of power capacitor, reactor and resistor.This method not only can harmonic inhabitation but also can compensating power, and structure is simple, is widely used always.But, because its impact by system parameters is comparatively large, and can not dynamic compensation be realized, therefore develop the method for active power filtering.

The equipment of active power filtering generally comprises Active Power Filter-APF, dynamic electric voltage recovery device, Research on Unified Power Quality Conditioner etc.These equipment can the Parameters variation of adaptive system, realizes dynamic compensation, improves the quality of power supply.The interface current transformer being applied to distributed power generation in system also can be used as active power filtering, utilizes the residual capacity of current transformer to carry out harmonic compensation, the effect of this namely versatile interface current transformer.

But single versatile interface current transformer can not the simultaneously current harmonics of compensation network side and the voltage distortion of load-side, especially contain the condition of harmonic wave at line voltage itself under.And Research on Unified Power Quality Conditioner can the distortion of simultaneously offset current and voltage, but it needs transformer, and equipment volume is huge and cost is higher.

Summary of the invention

The technical problem to be solved in the present invention is to provide a kind of micro-capacitance sensor supply power voltage based on twin inverter group cooperation control and grid current harmonic synchroballistic method, can improve the quality of power supply while not increasing compensation arrangement.

For solving the problems of the technologies described above, technical scheme of the present invention is: wouldn't write, identical with claim

The invention has the advantages that:

The structure of double nip current transformer parallel connection is adopted in the present invention, while output fundamental power, the harmonic wave of one current transformer to load supplying voltage compensates, and another current transformer compensates the harmonic current that load and a current transformer produce, and ensures the quality of power supply of the supply current of grid side.This method utilizes the interface current transformer of distributed generation system to improve the quality of power supply, without the need to the compensation arrangement increased, cost-saving, economical and practical, is convenient to promote.And the present invention adopts new control control method, it can save harmonic current and extract link and phase-locked loop, substantially reduces the computational burden of numerical control system.

Accompanying drawing explanation

Fig. 1 is double nip current transformer topological structure schematic diagram in parallel in the present invention.

Fig. 2 is current transformer A control strategy flow chart in the present invention.

Fig. 3 is current transformer B control strategy flow chart in the present invention.

Fig. 4 is the simulation waveform figure that the present invention only compensates supply power voltage harmonic wave;

Fig. 5 is the simulation waveform figure of the present invention's compensation harmonic electric current.

Fig. 6 is the simulation waveform figure that the present invention compensates supply power voltage and harmonic current simultaneously.

Fig. 7 be the present invention simultaneously bucking voltage and current harmonics time current transformer A simulation waveform figure.

Fig. 8 be the present invention simultaneously bucking voltage and current harmonics time current transformer B simulation waveform figure.

Embodiment

As shown in Figure 1, compensation method of the present invention is that its structure is specific as follows based on a kind of double nip current transformer topological structure in parallel:

Comprise the current transformer A1 and current transformer B2 that are arranged in parallel for a pair, current transformer A1 and current transformer B2 exchanges power with bulk power grid after being connected to points of common connection PCC respectively by respective filter 3,4; Wherein, current transformer A1 and current transformer B2 by six power switching modules composition three phase full bridges topology, the DC side bus capacitor V that the DC side parallel one of current transformer A1 and current transformer B2 is public _dC, filter 3,4 is by current transformer side filter inductance L ₁, grid side filter inductance L ₂with filter capacitor C _fcomposition, nonlinear-load 5 is connected on the grid side filter inductance L of current transformer A1 ₂with filter capacitor C _fbetween.

Compensation method in the present invention adopts the strategy of double convertor electric current and voltage cooperation control, and concrete grammar is as follows:

Step S1: when each sampling period starts, current transformer A utilize sample circuit to gather filter capacitor magnitude of voltage V _{c, C1}, points of common connection magnitude of voltage V _pCC, output current value I _{1, C1}with grid-connected current value I _{2, C1}, current transformer B utilizes sample circuit to gather output current value I _{1, C2}, grid-connected current value I _{2, C2}, points of common connection magnitude of voltage V _pCCwith the grid-connected current I of current transformer A _{2, C1}, and active power reference P _refwith reactive power reference Q _refby equipment user or upper strata dispatch command given, and the digital quantity after transforming is sent to the control module of each current transformer;

The control module of step S2: current transformer A adopts mixed-voltage Current Control Strategy to obtain reference voltage the control module of current transformer B adopts principal wave harmonic wave Current Control Strategy to obtain reference voltage

Step S3: current transformer A and current transformer B obtaining reference voltage after, according to sinusoidal pulse width modulation (SPWM) or space vector pulse width modulation (SVPWM), compare with triangular wave, obtain the duty cycle signals of switching tube, thus control opening and shutoff of converter switches pipe.

Wherein, be specially by sinusoidal wave pulse width adjustment method: reference voltage and triangular wave compare, when reference voltage is higher than triangle wave voltage, upper pipe provides Continuity signal, lower pipe provides cut-off signals, otherwise then goes up pipe and provide cut-off signals, and lower pipe provides Continuity signal, thus obtain the duty cycle signals of switching tube, the final output voltage controlling current transformer A and current transformer B.

As the present invention's execution mode more specifically:

In step S2: the reference voltage of current transformer A suppress part reference voltage and active damping part reference voltage to be added by output power part reference voltage, voltage harmonic to obtain; Be summarized in equation one namely

$V_{out,C1}^{*}=H_{PQ}\left(s\right)\·(I_{2,C1,ref}-I_{2,C1})+H_{Har}\left(s\right)\·(0-V_{C,C1})+H_{AD}\left(s\right)\·I_{1,C1};$

Wherein for the reference voltage of current transformer A, I _{2, C1, ref}for the output current of the reference signal of current transformer A, I _{2, C1}for grid-connected current, V _{c, C1}for the filter capacitor magnitude of voltage of current transformer A, I _{1, C1}for the output current value of current transformer A; H _pQ(s), H _har(s), H _aDs () is respectively the transfer function that first-harmonic follows the tracks of ratio resonant controller, harmonics restraint ratio resonant controller, Damping Scale controller, variable s is complex frequency;

Because power control section is divided into first-harmonic to control, under harmonic frequency, the gain of transfer function is very little.Meanwhile, voltage harmonic suppressing portion is divided into harmonic controling, and under fundamental frequency, the gain of transfer function is very little.Therefore these two parts are decoupling zeros, mutually affect hardly.This is also the basis that mixed-voltage Current Control Strategy can play a role.

Current transformer A output power part is used for exporting the active power that sends of distributed power source and reactive power, and its reference voltage is H _pQ(s) (I _{2, C1, ref}-I _{2, C1}), specifically describe as follows: by the grid-connected current value I obtained that samples _{2, C1}with points of common connection magnitude of voltage V _pCCthe active power of output P of current transformer A is obtained by power calculation _c1and reactive power Q _c1; Then, the active-power P of Reference Signal _ref, reactive power Q _refwith the active-power P of actual signal _c1, reactive power Q _c1input pi controller PI, obtains the output current I of reference signal _{2, C1, ref}; The output current I of this reference signal _{2, C1, ref}with the grid-connected current I of actual signal _{2, C1}subtract each other, difference input first-harmonic follows the tracks of ratio resonant controller H _pQ, obtain the reference voltage that current transformer A power control section is divided.

Wherein, the output current I of reference signal _{2, C1, ref}by the active-power P of reference signal _ref, reactive power Q _refwith the active-power P of actual signal _c1, reactive power Q _c1difference input pi controller PI obtain;

The transfer function of pi controller PI is

Wherein variable s is complex frequency, k _{pI_p}for proportionality coefficient, value 1 ~ 50; k _{pI_i}for integral coefficient, value 10 ~ 800.

Ratio resonant controller H _pQtransfer function

Wherein variable s is complex frequency, k _{pI, C1}for proportional gain, value 0.1 ~ 1; k _i,ffor first-harmonic resonance gain, value 10 ~ 800; w _cfor bandwidth, value 3 ~ 20; w ₀centered by angular frequency, w ₀=2 π f ₀, f ₀=50Hz.

Current transformer A voltage harmonic suppression part is used for improving the quality of power supply of load supplying voltage, and its reference voltage is H _har(s) (V _{c, C1, ref}-V _{c, C1}), specifically describe as follows: by voltage harmonic reference value V _{c, C1, ref}select the 0 filter capacitor magnitude of voltage V obtained with sampling _{c, C1}subtract each other, difference input harmonics suppresses ratio resonant controller H _har, obtain the reference voltage of current transformer A voltage harmonic suppression part; Ratio resonant controller H _hartransfer function

$H_{Har}\left(s\right)=k_{p2,c1}+\underset{h=5,7,11,13}{\Σ}\frac{2k_{v,h}{\mathrm{\ω}}_{c}s}{S^2+2{\mathrm{\ω}}_{c}s+{(h\·{\mathrm{\ω}}_o)}^2}$

Wherein variable s is complex frequency, and h is harmonic number, and low-order harmonic main in system is 5,7,11,13 times; k _{p2, C1}for proportional gain, value 0.1 ~ 1; k _v,hfor voltage harmonic resonance gain, value 10 ~ 800; w _cfor bandwidth, value 3 ~ 20; w ₀centered by angular frequency, w ₀=2 π f ₀, f ₀=50Hz.

Current transformer A active damping part is for improving the damping of system, and suppress current transformer to produce resonance, its reference voltage is H _aD(s) I _{1, C1}, specifically describe as follows: by the current transformer A output current value I obtained that samples _{1, C1}through Damping Scale controller H _aD, obtain the reference voltage of current transformer A active damping part; Proportional controller H _aDtransfer function H _aD(s)=k _aD; Wherein k _aDfor proportional control factor, value 1 ~ 3.

In this step, the harmonic voltage suppression of current transformer A and fundamental current are followed the tracks of two links and all be have employed the control of ratio resonance.Due to the frequency selective characteristic of ratio resonant controller, it is decoupling zeros that harmonic voltage suppression and fundamental current follow the tracks of two links, is independent of each other.Under harmonic frequency, present the characteristic of voltage source, when Voltage Reference is set to zero, supply power voltage harmonic wave can be effectively suppressed.But under fundamental frequency, present the characteristic of current source, can according to command output power.

In step S2: the reference voltage of current transformer B the reference voltage of the reference voltage divided by power control section, current harmonics suppression part and the reference voltage of active damping part are added and obtain; Be summarized in equation two namely:

$V_{out,C2}^{*}=H_{PQ}\left(s\right)\·(I_{2,C2,ref}-I_{2,C2})+H_{Har}\left(s\right)\·(I_{2,C1}-I_{2,C2})+H_{AD}\left(s\right)\·I_{1,C2};$

Wherein for the reference voltage of current transformer B, I _{2, C2, ref}for the output current of the reference signal of current transformer B, I _{2, C1}for the grid-connected current of current transformer A, I _{2, C2}for the grid-connected current of current transformer B, I _{1, C2}for the output current value of current transformer B; H _pQ(s), H _har(s), H _aDs () is respectively the transfer function that first-harmonic follows the tracks of ratio resonant controller, harmonics restraint ratio resonant controller, Damping Scale controller, variable s is complex frequency.

The power control section of current transformer B divides reference voltage to be H _pQ(s) (I _{2, C2, ref}-I _{2, C2}), specifically describe as follows: by the grid-connected current value I obtained that samples _{2, C2}with points of common connection magnitude of voltage V _pCC, calculate the active power of output P of current transformer B _c2and reactive power Q _c2; Then, the active-power P of Reference Signal _ref, reactive power Q _refwith the active-power P of actual signal _c2, reactive power Q _c2input pi controller PI, obtains the grid-connected current I of reference signal _{2, C2, ref}; The output current I of this reference signal _{2, C2, ref}with the grid-connected current I of actual signal _{2, C2}subtract each other, difference input first-harmonic follows the tracks of ratio resonant controller H _pQ, obtain the reference voltage composition that power control section is divided.

Wherein, the output current I of reference signal _{2, C2, ref}by the active-power P of reference signal _ref, reactive power Q _refwith the active-power P of actual signal _c2, reactive power Q _c2difference input pi controller PI obtain;

The transfer function of pi controller PI is

Wherein variable s is complex frequency, k _{pI_p}for proportionality coefficient, value 1 ~ 50; k _{pI_i}for integral coefficient, value 10 ~ 800.

Ratio resonant controller H _pQtransfer function

Wherein variable s is complex frequency, k _{pI, C2}for proportional gain, value 0.1 ~ 1; k _i,ffor first-harmonic resonance gain, value 10 ~ 800; w _cfor bandwidth, value 3 ~ 20; w ₀centered by angular frequency, w ₀=2 π f ₀, f ₀=50Hz.

The current harmonics suppression part of current transformer B is used for the harmonic current of compensating non-linear load and current transformer A, and improve the quality of power supply of grid side electric current, its reference voltage is H _har(s) (I _{2, C1}-I _{2, C2}), specifically describe as follows: by the current transformer A grid-connected current value I obtained that samples _{2, C1}conduct with reference to electric current, namely the harmonic current component in this sampled value is the offset current that current transformer B needs to export; With reference to electric current I _{2, C1}with the grid-connected current value I of current transformer B _{2, C2}subtract each other, difference input harmonics suppresses ratio resonant controller H _har, obtain the reference voltage composition of current harmonics suppression part; Ratio resonant controller H _hartransfer function

$H_{Har}\left(s\right)=k_{p2,c2}+\underset{h=5,7,11,13}{\Σ}\frac{2k_{i,h}{\mathrm{\ω}}_{c}s}{s^2+2{\mathrm{\ω}}_{c}s+{(h\·{\mathrm{\ω}}_o)}^2};$

Wherein variable s is complex frequency, and h is harmonic number, and low-order harmonic main in system is 5,7,11,13 times; k _{p2, C2}for proportional gain, value 0.1 ~ 1; k _i,hfor current harmonics resonance gain, value 10 ~ 800; w _cfor bandwidth, value 3 ~ 20; w ₀centered by angular frequency, w ₀=2 π f ₀, f ₀=50Hz.

The active damping part reference voltage of current transformer B is H _aD(s) I _{1, C2}, specifically describe as follows: obtain output current of converter value I by sampling _{1, C2}through Damping Scale controller, obtain the reference voltage composition of active damping part; Proportional controller H _aDtransfer function H _aD(s)=k _aD; Wherein k _aDfor proportional control factor, value 1 ~ 3.

In this step, the current harmonics elimination of current transformer B and fundamental current are followed the tracks of two links and are also used the control of ratio resonance, and therefore current harmonics elimination and fundamental current follow the tracks of two links is also decoupling zero, is independent of each other.For current harmonics elimination link, output current is very little under fundamental frequency relative to the amplitude gain of harmonic compensation current reference, and under specific harmonic frequency, has the characteristic of null gain, zero phase angle gain.Therefore, harmonic wave extracts link and can save, and the signal obtained of sampling can directly apply to closed-loop control.But follow the tracks of link for fundamental current, output current is very little under harmonic frequency relative to the amplitude gain of fundamental power current reference, and under fundamental frequency, has the characteristic of null gain, zero phase angle gain.This illustrates that phase-locked loop can save when exporting fundamental power.

Fig. 4-8 is simulation waveform figure of the present invention, and in figure, a, b, c represent the three-phase phase-sequence of electric power system.Build simulation model as shown in Figure 1 with Matlab/Simulink, line voltage contains the harmonic distortion of stable state, and line voltage THD is 5.6%.While current transformer active power of output, respectively to only compensating supply power voltage harmonic wave, an offset current harmonic wave, voltage and current harmonic wave carry out simulating, verifying under compensating three kinds of situations simultaneously.

Fig. 4 is the situation only compensating supply power voltage harmonic wave, and can find out in figure, now load supplying voltage THD is only 1.48%, but power network current THD is 12.28%.

Fig. 5 is a situation for compensation harmonic electric current, can find out in figure, and now power network current THD reduces greatly, be 4.57%, and load supplying voltage THD is 6.45%.Fig. 4-6 is the coordination control strategy adopting electric current and voltage of the present invention simultaneously to compensate.

Figure 6 shows that line voltage and current waveform, can find out, current waveform is close to sinusoidal, and electric current THD is 3.54%.

Figure 7 shows that the waveforms such as the capacitance voltage of current transformer A, output current.Control objectives due to current transformer A is the quality of power supply improving load supplying voltage.Can find out, the waveform of supply power voltage is almost sine, and voltage THD is 2.28%, illustrates that the harmonic voltage of current transformer A suppresses very effective.

Figure 8 shows that the waveforms such as the capacitance voltage of current transformer B, output current, its control objectives is the harmonic current that compensating load and current transformer A produce.Power network current THD is 3.54% as shown in Figure 4, illustrates that the compensation effect of current transformer B is good.

Conclusion: micro-capacitance sensor supply power voltage therefore proposed by the invention and the harmonic compensation method of power network current practical, the loss of system can be reduced, ensure system stable operation.And harmonic current extraction link and phase-locked loop link can be saved, substantially reducing the amount of calculation of numerical control system, is a kind of method of the raising quality of power supply be worthy to be popularized.

Claims (11)

1., based on micro-capacitance sensor supply power voltage and the grid current harmonic synchroballistic method of twin inverter group cooperation control, it is characterized in that:

Described method based on double nip current transformer topological structure in parallel be specially: comprise the current transformer A and current transformer B that are arranged in parallel for a pair, described current transformer A and current transformer B exchanges power with bulk power grid after being connected to points of common connection PCC respectively by respective filter, wherein, current transformer A and current transformer B by six power switching modules composition three phase full bridges topology, the DC side bus capacitor V that the DC side parallel one of current transformer A and current transformer B is public _dC, filter is by current transformer side filter inductance L ₁, grid side filter inductance L ₂with filter capacitor C _fcomposition, nonlinear-load is connected on the grid side filter inductance L of current transformer A ₂with filter capacitor C _fbetween;

Described compensation method adopts the strategy of double convertor electric current and voltage cooperation control, and concrete grammar is as follows:

Step S1 is when each sampling period starts, and current transformer A utilizes sample circuit to gather filter capacitor magnitude of voltage V _{c, C1}, points of common connection magnitude of voltage V _pCC, output current value I _{1, C1}with grid-connected current value I _{2, C1}, current transformer B utilizes sample circuit to gather output current value I _{1, C2}, grid-connected current value I _{2, C2}, points of common connection magnitude of voltage V _pCCwith the grid-connected current I of current transformer A _{2, C1}, and active power reference P _refwith reactive power reference Q _refby equipment user or upper strata dispatch command given, and the digital quantity after transforming is sent to the control module of each current transformer;

The control module of step S2 current transformer A adopts mixed-voltage Current Control Strategy to obtain reference voltage the control module of current transformer B adopts principal wave harmonic wave Current Control Strategy to obtain reference voltage

Step S3 current transformer A and current transformer B is obtaining reference voltage after, by according to sinusoidal pulse width modulation (SPWM) or space vector pulse width modulation (SVPWM), compare with triangular wave, obtain the duty cycle signals of switching tube, thus control opening and shutoff of converter switches pipe, the final output voltage controlling current transformer A and current transformer B.

2. the micro-capacitance sensor supply power voltage based on twin inverter group cooperation control according to claim 1 and grid current harmonic synchroballistic method, is characterized in that: the reference voltage of described current transformer A suppress part reference voltage and active damping part reference voltage to be added by output power part reference voltage, voltage harmonic to obtain; Namely

$V_{out,C1}^{*}=H_{PQ}\left(s\right)\·(I_{2,C1,ref}-I_{2,C1})+H_{Har}\left(s\right)\·(0-V_{C,C1})+H_{AD}\left(s\right)\·I_{1,C1};$

Wherein for the reference voltage of current transformer A, I _{2, C1, ref}for the output current of the reference signal of current transformer A, I _{2, C1}for grid-connected current, V _{c, C1}for the filter capacitor magnitude of voltage of current transformer A, I _{1, C1}for the output current value of current transformer A; H _pQ(s), H _har(s), H _aDs () is respectively the transfer function that first-harmonic follows the tracks of ratio resonant controller, harmonics restraint ratio resonant controller, Damping Scale controller, variable s is complex frequency;

The reference voltage of current transformer A output power part specifically describes as follows: by the grid-connected current value I obtained that samples _{2, C1}with points of common connection magnitude of voltage V _pCCthe active power of output P of current transformer A is obtained by power calculation _c1and reactive power Q _c1; Then, the active-power P of Reference Signal _ref, reactive power Q _refwith the active-power P of actual signal _c1, reactive power Q _c1input pi controller PI, obtains the output current I of reference signal _{2, C1, ref}; The output current I of this reference signal _{2, C1, ref}with the grid-connected current I of actual signal _{2, C1}subtract each other, difference input first-harmonic follows the tracks of ratio resonant controller H _pQ, obtain the reference voltage that current transformer A power control section is divided;

It is as follows that current transformer A voltage harmonic suppresses the reference voltage of part to specifically describe: by voltage harmonic reference value 0 and the filter capacitor magnitude of voltage V obtained that samples _{c, C1}subtract each other, difference input harmonics suppresses ratio resonant controller H _har, obtain the reference voltage of current transformer A voltage harmonic suppression part;

The reference voltage of current transformer A active damping part specifically describes as follows: by the current transformer A output current value I obtained that samples _{1, C1}through Damping Scale controller H _aD, obtain the reference voltage of current transformer A active damping part.

3. the micro-capacitance sensor supply power voltage based on twin inverter group cooperation control according to claim 2 and grid current harmonic synchroballistic method, is characterized in that: the output current I of described reference signal _{2, C1, ref}by the active-power P of reference signal _ref, reactive power Q _refwith the active-power P of actual signal _c1, reactive power Q _c1difference input pi controller PI obtain; The transfer function of pi controller PI is

Wherein variable s is complex frequency, k _{pI_p}for proportionality coefficient, value 1 ~ 50; k _{pI_i}for integral coefficient, value 10 ~ 800.

4. the micro-capacitance sensor supply power voltage based on twin inverter group cooperation control according to claim 2 and grid current harmonic synchroballistic method, is characterized in that: ratio resonant controller H in described current transformer A _pQtransfer function

Wherein variable s is complex frequency, k _{pI, C1}for proportional gain, value 0.1 ~ 1; k _i,ffor first-harmonic resonance gain, value 10 ~ 800; w _cfor bandwidth, value 3 ~ 20; w ₀centered by angular frequency, w ₀=2 π f ₀, f ₀=50Hz.

5. the micro-capacitance sensor supply power voltage based on twin inverter group cooperation control according to claim 2 and grid current harmonic synchroballistic method, is characterized in that: ratio resonant controller H in described current transformer A _hartransfer function

$H_{Har}\left(s\right)=k_{p2,c1}+\underset{h=5,7,11,13}{\Σ}\frac{2k_{v,h}{\mathrm{\ω}}_{c}s}{s^2+2{\mathrm{\ω}}_{c}s+{(h\·{\mathrm{\ω}}_o)}^2}$

Wherein variable s is complex frequency, and h is harmonic number, and low-order harmonic main in system is 5,7,11,13 times; k _{p2, C1}for proportional gain, value 0.1 ~ 1; k _v,hfor voltage harmonic resonance gain, value 10 ~ 800; w _cfor bandwidth, value 3 ~ 20; w ₀centered by angular frequency, w ₀=2 π f ₀, f ₀=50Hz.

6. the micro-capacitance sensor supply power voltage based on twin inverter group cooperation control according to claim 2 and grid current harmonic synchroballistic method, is characterized in that: proportional controller H in described current transformer A _aDtransfer function H _aD(s)=k _aD;

Wherein k _aDfor proportional control factor, value 1 ~ 3.

7. the micro-capacitance sensor supply power voltage based on twin inverter group cooperation control according to claim 1 and grid current harmonic synchroballistic method, is characterized in that: the reference voltage of described current transformer B the reference voltage of the reference voltage divided by power control section, current harmonics suppression part and the reference voltage of active damping part are added and obtain; Namely

$V_{out,C2}^{*}=H_{PQ}\left(s\right)\·(I_{2,C2,ref}-I_{2,C2})+H_{Har}\left(s\right)\·(I_{2,C1}-I_{2,C2})+H_{AD}\left(s\right)\·I_{1,C2};$

Wherein for the reference voltage of current transformer B, I _{2, C2, ref}for the output current of the reference signal of current transformer B, I _{2, C1}for the grid-connected current of current transformer A, I _{2, C2}for the grid-connected current of current transformer B, I _{1, C2}for the output current value of current transformer B; H _pQ(s), H _har(s), H _aDs () is respectively the transfer function that first-harmonic follows the tracks of ratio resonant controller, harmonics restraint ratio resonant controller, Damping Scale controller, variable s is complex frequency;

The power control section of current transformer B divides reference voltage specific descriptions as follows: by the grid-connected current value I obtained that samples _{2, C2}with points of common connection magnitude of voltage V _pCC, calculate the active power of output P of current transformer B _c2and reactive power Q _c2; Then, the active-power P of Reference Signal _ref, reactive power Q _refwith the active-power P of actual signal _c2, reactive power Q _c2input pi controller PI, obtains the grid-connected current I of reference signal _{2, C2, ref}; The output current I of this reference signal _{2, C2, ref}with the grid-connected current I of actual signal _{2, C2}subtract each other, difference input first-harmonic follows the tracks of ratio resonant controller H _pQ, obtain the reference voltage composition that power control section is divided;

The current harmonics of current transformer B suppresses part reference voltage specific descriptions as follows: by the current transformer A grid-connected current value I obtained that samples _{2, C1}conduct with reference to electric current, namely the harmonic current component in this sampled value is the offset current that current transformer B needs to export; With reference to electric current I _{2, C1}with the grid-connected current value I of current transformer B _{2, C2}subtract each other, difference input harmonics suppresses ratio resonant controller H _har, obtain the reference voltage composition of current harmonics suppression part;

The active damping part reference voltage of current transformer B specifically describes as follows: obtain output current of converter value I by sampling _{1, C2}through Damping Scale controller, obtain the reference voltage composition of active damping part.

8. the micro-capacitance sensor supply power voltage based on twin inverter group cooperation control according to claim 7 and grid current harmonic synchroballistic method, is characterized in that: the output current I of described reference signal _{2, C2, ref}by the active-power P of reference signal _ref, reactive power Q _refwith the active-power P of actual signal _c2, reactive power Q _c2difference input pi controller PI obtain; The transfer function of pi controller PI is

Wherein variable s is complex frequency, k _{pI_p}for proportionality coefficient, value 1 ~ 50; k _{pI_i}for integral coefficient, value 10 ~ 800.

9. the micro-capacitance sensor supply power voltage based on twin inverter group cooperation control according to claim 7 and grid current harmonic synchroballistic method, is characterized in that: ratio resonant controller H in described current transformer B _pQtransfer function

Wherein variable s is complex frequency, k _{pI, C2}for proportional gain, value 0.1 ~ 1; k _i,ffor first-harmonic resonance gain, value 10 ~ 800; w _cfor bandwidth, value 3 ~ 20; w ₀centered by angular frequency, w ₀=2 π f ₀, f ₀=50Hz.

10. the micro-capacitance sensor supply power voltage based on twin inverter group cooperation control according to claim 7 and grid current harmonic synchroballistic method, is characterized in that: ratio resonant controller H in described current transformer B _hartransfer function

$H_{Har}\left(s\right)=k_{p2,c2}+\underset{h=5,7,11,13}{\Σ}\frac{2k_{i,h}{\mathrm{\ω}}_{c}s}{s^2+2{\mathrm{\ω}}_{c}s+{(h\·{\mathrm{\ω}}_o)}^2};$

Wherein variable s is complex frequency, and h is harmonic number, and low-order harmonic main in system is 5,7,11,13 times; k _{p2, C2}for proportional gain, value 0.1 ~ 1; k _i,hfor current harmonics resonance gain, value 10 ~ 800; w _cfor bandwidth, value 3 ~ 20; w ₀centered by angular frequency, w ₀=2 π f ₀, f ₀=50Hz.

The 11. micro-capacitance sensor supply power voltages based on twin inverter group cooperation control according to claim 7 and grid current harmonic synchroballistic method, is characterized in that: proportional controller H in described current transformer B _aDtransfer function H _aD(s)=k _aD;

Wherein k _aDfor proportional control factor, value 1 ~ 3.