CN105811400A - Self-adaptive control method for modes of low-voltage microgrid - Google Patents

Abstract

The invention relates to a self-adaptive control method for modes of a low-voltage microgrid. The method comprises the following steps of (1) obtaining power operation parameters of the low-voltage microgrid and constructing a droop control model of the low-voltage microgrid based on a virtual synchronous generator; (2) adding a low-pass filter between a virtual synchronous generator control link and a filter inductor to carry out voltage and current sampling of the filter inductor in the droop control model of the low-voltage microgrid based on the virtual synchronous generator; (3) adding a stability controller between the virtual synchronous generator control link and the reactive power and active power reference value signals while adding a reactive integral gain link between the stability controller and the reactive power reference value signal to obtain a modified droop control model of the low-voltage microgrid; and (4) carrying out mode switching on the low-voltage microgrid according to the modified droop control model of the low-voltage microgrid. In comparison with the prior art, the method has the advantages of disturbance elimination, stable switching, high stability, strong practicability and the like.

Description

A kind of self-adaptation control method of low pressure micro-capacitance sensor pattern

Technical field

The present invention relates to micro-capacitance sensor and run control strategy wave analysis field, especially relate to the self-adaptation control method of a kind of low pressure micro-capacitance sensor pattern.

Background technology

Recently as the development of distributed power source, at energy consumption, when energy security is increasingly serious with environmental problem, the micro-capacitance sensor containing distributed power source (DistributedGeneration, DG) receives more and more attention.Along with the access of a large amount of DG, the scale of micro-capacitance sensor is also increasing so that the operation control method of conventional electric power system is no longer applicable to micro-capacitance sensor.Micro-capacitance sensor is by the low voltage power distribution network of multiple DG, energy storage device, load and control system set, not only can be incorporated into the power networks but also can be operated in island mode, and this just requires that control system guarantee two kinds of operational modes of micro-capacitance sensor take over seamlessly.When containing a large amount of DG, how to realize one of efficient, stable control important directions becoming the research of future studies micro-capacitance sensor.

Micro-capacitance sensor major part DG is electronic power inversion type interface, lacks synchronous generator revolving property in tradition electrical network, and DG is responsible for the links such as the adjustment of micro-capacitance sensor frequency, Voltage Cortrol, PFC, and two kinds of running statuses of micro-capacitance sensor require that the DG link being responsible for is different.When being incorporated into the power networks, power distribution network provides frequency and voltage support for it, adopts PQ droop control, and output is determined by setting value；During islet operation, sufficient amount of DG must be had to provide power to support for micro-capacitance sensor and to ensure that micro-capacitance sensor frequency and voltage run in critical field, realize load capacity reasonable distribution between DG, use V/f droop control, adopt the droop characteristic between frequency and active power and the reactive power of terminal voltage and output that the inverter of droop control method is equal in high-voltage electric power system synchronous generator.

For this new problem, 2 kinds of operational modes of micro-capacitance sensor have been separately designed different control methods by existing low pressure micro-capacitance sensor patten transformation control method, namely during operational mode conversion, control strategy also to be changed accordingly, so easily cause in control model transfer lag and control method handoff procedure and can produce bigger impact, even cause operational mode convert failed.Furthermore switch without being controlled mode when micro-capacitance sensor patten transformation to realize the existing control method of unification of micro-capacitance sensor patten transformation control strategy, but do not consider micro-capacitance sensor frequency and voltage regulation problem in patten transformation transient process, therefore find a kind of control method that can effectively realize micro-capacitance sensor patten transformation necessary.

Summary of the invention

Defect that the purpose of the present invention is contemplated to overcome above-mentioned prior art to exist and a kind of self-adaptation control method eliminating high, the practical low pressure micro-capacitance sensor pattern of disturbance, steadily switching, stability is provided.

The purpose of the present invention can be achieved through the following technical solutions:

The self-adaptation control method of a kind of low pressure micro-capacitance sensor pattern, carries out being incorporated into the power networks and the switching of safety and steady between two kinds of operational modes of islet operation in order to realize low pressure micro-capacitance sensor, eliminates transient current when switching and voltge surge, comprises the following steps:

1) obtain the operation power parameter of low pressure micro-capacitance sensor, build the low pressure micro-capacitance sensor droop control model based on virtual synchronous electromotor；

2) based on, in the low pressure micro-capacitance sensor droop control model of virtual synchronous electromotor, increasing low pass filter between virtual synchronous generator control link and filter inductance, be filtered inductive drop current sample；

3) between virtual synchronous generator control link and reactive power and active power reference value signal, stability controller is increased, between stability controller and reactive power reference qref signal, increase idle storage gain link, the low pressure micro-capacitance sensor droop control model after being improved simultaneously；

4) according to the low pressure micro-capacitance sensor droop control model after improving, low pressure micro-capacitance sensor is carried out pattern switching, eliminate transient current and voltge surge.

Described virtual synchronous generator control link operation logic is:

$\left\{\begin{array}{c}e={\mathrm{\ω}}_e{M}_f{i}_{e}sin\mathrm{\θ}\\ J\mathrm{\ω}s=\frac{P_T-P_e}{{\mathrm{\ω}}^{*}}+D({\mathrm{\ω}}^{*}-\mathrm{\ω})\\ Q=\frac{3}{2}{M}_f{i}_{e}isin\mathrm{\θ}\end{array}\right.$

Wherein, P_TFor mechanical output, P_eFor electromagnetic power, J is the rotary inertia of rotor, ω^*For reference angular rate, D is permanent damped coefficient, and e is induction electromotive force, M_fFor the maximum induction between Exciting Windings for Transverse Differential Protection and magnetic field winding, i_eFor exciting current, θ is electromotor electrical angle, ω_eFor faradic current angular frequency, ω is reference angle frequency, and i is reference current, and Q is that inverter output is idle, and s is differential coefficient.

Described step 3) between stability controller and reactive power reference qref signal, increase idle storage gain link after control process be:

$V=V^{*}-m\[Q^{*}-(n_1{Q}_n+\frac{n_2}{s}{Q}_g)\]$

Wherein, V is voltage magnitude reference value, Q_nFor reactive power reference qref, m is sagging coefficient, V^*For by the calculated voltage magnitude of power controller, n₁And n₂When being respectively incorporated into the power networks, micro-capacitance sensor output is idle detects calculated idle gain coefficient, Q with electrical network_nFor inverter output reactive power, Q_gThe reactive power of inverter it is supplied to for electrical network.

Described step 3) in the mathematical model of stability controller be:

$\left\{\begin{array}{c}\mathrm{\Δ}f={\mathrm{\Δf}}^{\′}+(K_{3\mathrm{\θ}}+\frac{K_{3\mathrm{\θ}}}{s})({\mathrm{\ω}}_g-{\mathrm{\ω}}_m)\\ \mathrm{\Δ}U={\mathrm{\ΔU}}^{\′}+k_{\mathrm{\δ}}(K_{4\mathrm{\θ}}+\frac{K_{4\mathrm{\θ}}}{s})({\mathrm{\δ}}_g-{\mathrm{\δ}}_m)+k_p(K_{4\mathrm{\θ}}+\frac{K_{4\mathrm{\θ}}}{s})(P_g-P_m)\end{array}\right.$

Wherein, wherein, Δ f is the electric voltage frequency after superposition, and Δ f ' is primary voltage frequency, K_3θAnd K_4θFor gain, ω_gFor power distribution network angular rate, ω_mFor micro-capacitance sensor angular rate, Δ U is the amplitude deviation after superposition, and Δ U ' is open width value deviation, k_δAnd k_pIt is respectively U/ δ and U/P gain coefficient, δ_gFor the merit angle of power distribution network output, δ_mFor the merit angle of micro-capacitance sensor output, P_gFor power distribution network output, P_mFor micro-capacitance sensor output.

Described step 4) in micro-grid connection run time adopt PQ droop control, during islet operation adopt V/f droop control.

The active power under low pressure micro-capacitance sensor droop control model grid-connect mode after described improvement and reactive power calculate equation:

$\left\{\begin{array}{c}{p}_g=\frac{{\mathrm{EU}}_{pcc}}{Z}cos({\mathrm{\θ}}_{pcc}-\mathrm{\θ})-\frac{U_{pcc}^2}{Z}{\mathrm{cos\θ}}_{pcc}\\ q_g=\frac{{\mathrm{EU}}_{pcc}}{Z}sin({\mathrm{\θ}}_{pcc}-\mathrm{\θ})-\frac{U_{pcc}^2}{Z}{\mathrm{sin\θ}}_{pcc}\end{array}\right.$

Wherein, p_gAnd q_gMeritorious and the reactive power setting value of distributed power source during for low pressure micro-grid connection state, Z is low pressure micro-capacitance sensor line impedance, θ_pccFor PCC point voltage phase angle, θ is inverter output voltage phase angle, and E is inverter output voltage amplitude, U_pccFor PCC point voltage amplitude.

Compared with prior art, the invention have the advantages that

One, eliminate disturbance, steadily switching: the technical program is for micro-capacitance sensor mode operation transformation process, propose a kind of low pressure micro-capacitance sensor mode adaptive control method, the transient characterisitics of the inverter lacking inertia are improved by introducing Virtual Torque and damped coefficient, combined with virtual synchronous generator method also adds simulation low-pass filter module and idle integral control module meets two kinds of operational modes different service requirements to DG, compared to tradition micro-capacitance sensor mode adaptive control strategy, the technical program improves the operation inertia of micro-capacitance sensor, operational mode change period control method is avoided to switch the micro-capacitance sensor disturbance caused；

Two, stability is high: the technical program devises stability controller and improves the system control speed of response, simultaneously, it is ensured that micro-capacitance sensor stability after being subject to sudden load change and State Transferring disturbance.

Three, practical: the technical program principle is simple, it is achieved easily, to there is certain engineering use value.

Accompanying drawing explanation

Fig. 1 is the low pressure micro-capacitance sensor droop control block diagram after improving.

Fig. 2 is the control principle drawing of the low pressure micro-capacitance sensor droop control after improving.

Figure (3a) is DG1 and DG2 active power of output figure in two kinds of operational mode transformation processs of micro-capacitance sensor.

Figure (3b) is DG1 and DG2 output reactive power figure in two kinds of operational mode transformation processs of micro-capacitance sensor.

Figure (3c) is PCC point voltage variation diagram in two kinds of operational mode transformation processs of micro-capacitance sensor.

Figure (3d) is PCC dot frequency variation diagram in two kinds of operational mode transformation processs of micro-capacitance sensor.

PCC dot frequency adjustment figure when Fig. 4 is to be subject to load fluctuation under micro-capacitance sensor islet operation pattern.

Detailed description of the invention

Below in conjunction with the drawings and specific embodiments, the present invention is described in detail.

Embodiment:

As it is shown in figure 1, figure is the low pressure micro-capacitance sensor droop control block diagram after improving.

As in figure 2 it is shown, the control principle drawing that figure is the low pressure micro-capacitance sensor droop control after improving, if P_TFor mechanical output, P_eFor electromagnetic power, J is the rotary inertia (kg.m of rotor²), ω^*For reference angular rate, D is permanent damped coefficient, and e is induction electromotive force, M_fFor the maximum induction between Exciting Windings for Transverse Differential Protection and magnetic field winding, i_eFor exciting current, θ is electromotor electrical angle.

The present invention comprises the following steps:

A, according to synchronous generator operation logic, the mathematical model such as following formula of virtual synchronous electromotor (VSG):

$\left\{\begin{array}{c}e={\mathrm{\ω}}_e{M}_f{i}_{e}sin\mathrm{\θ}\\ J\mathrm{\ω}s=\frac{P_T-P_e}{{\mathrm{\ω}}^{*}}+D({\mathrm{\ω}}^{*}-\mathrm{\ω})\\ Q=\frac{3}{2}{M}_f{i}_{e}isin\mathrm{\θ}\end{array}\right.$

B, set V_nAnd Q_nVoltage magnitude and reactive power reference qref respectively；M is sagging coefficient；V^*For by the calculated voltage magnitude of power controller.Tradition droop control equation is as follows:

V^*=V_n-m(Q-Q_n)

C, system are for Reactive Power Control link outer when needing removal to be incorporated into the power networks when micro-capacitance sensor island operation state in the control of State Transferring.Not only increase simulation low-pass filter module herein and also add idle storage gain.In adjustment process, low pass filter is similar to the energy attenuation equation of synchronous generator, and reactive power change controls to be adjusted by PI, improves electric voltage frequency and follows the trail of efficiency, and idle governing equation is:

$V=V^{*}-m\[Q^{*}-(n_1{Q}_n+\frac{n_2}{s}{Q}_g)\]$

Wherein n₁And n₂When being respectively incorporated into the power networks, micro-capacitance sensor output is idle detects calculated idle gain coefficient with electrical network, and τ is simulation low-pass filter time constant.

Q_nAnd P_nFor inverter active power of output and reactive power, Q_gThe reactive power of inverter it is supplied to, the control process of lower the put forward control strategy of the surface analysis present invention for electrical network:

1 and net state under Qg be not zero and determined by setting value, the output of DG is by system voltage and frequency influence.The simulation low-pass filter module introduced under grid-connect mode can regard the rotor energy attenuation equation of synchronous generator in conventional electric power system as.And net state hangs down at present and controls to control to adjust the reactive power of injection, and system distributes reactive power according to DG reactive power capacity under net state, so needing to increase Reactive Power Control link in the stage of being incorporated into the power networks, herein in institute's extracting method, and under net state, active power and reactive power calculating equation are:

$\left\{\begin{array}{c}{p}_g=\frac{{\mathrm{EU}}_{pcc}}{Z}cos({\mathrm{\θ}}_{pcc}-\mathrm{\θ})-\frac{U_{pcc}^2}{Z}{\mathrm{cos\θ}}_{pcc}\\ q_g=\frac{{\mathrm{EU}}_{pcc}}{Z}sin({\mathrm{\θ}}_{pcc}-\mathrm{\θ})-\frac{U_{pcc}^2}{Z}{\mathrm{sin\θ}}_{pcc}\end{array}\right.$

P in formula_gAnd q_gDuring for also net state, DG gains merit and idle setting value, and Z=R+jX is micro-capacitance sensor line impedance, θ_pccFor PCC point voltage phase angle, θ is inverter output voltage phase angle, and E is inverter output voltage amplitude, U_pccFor PCC point voltage amplitude.

2, needing during island operation state to remove the Reactive Power Control ring that inverter is exported by electrical network, namely during island operation state, during tradition droop control, bulk power grid is supplied to the reactive power of inverter is 0, namely sets Qg=0, has automatically removed the idle controlling unit of outer shroud.The sagging coefficient of tradition droop control is fixing can only carry out proportion adjustment, dynamic property is controlled to adjust by sagging index impacts under micro-capacitance sensor island state, the introducing of the idle storage gain of context of methods makes parameter can change with situation, improve micro-capacitance sensor inertia, alleviate micro-capacitance sensor and be subject to the temporary impact of load disturbance, be conducive to micro-capacitance sensor island operation state stable, rapid dynamic response speed.In micro-grid connection process, DG output should being made to be smoothly transitted into value and power reference, in order to reduce because fast power changes the system shock caused, improve micro-capacitance sensor and be subject to the Ability of Resisting Disturbance of sudden load change, this patent have also been devised stability controller.

3, the disturbance that micro-capacitance sensor is subject to generally comprises sudden load change and state switching etc., and state switching is the maximum perturbation that micro-capacitance sensor is subject to, gather micro-capacitance sensor merit angle herein, angular rate and active power deviation pass through PI control design case stability controller, and the premise that micro-capacitance sensor remains stable for running is exactly the stable operation of voltage and frequency.In formula: Δ f ', Δ U ' respectively primary voltage frequency and amplitude deviation；Electric voltage frequency after Δ f, Δ U respectively superposition and amplitude deviation；ω, U, δ be angular rate respectively, the merit angle of voltage magnitude and microgrid output, k_δAnd k_pRespectively U/ δ and U/P gain coefficient, subscript g and m represents power distribution network and micro-capacitance sensor respectively, and wherein merit angle δ is tried to achieve by active power and reactive power setting value:

$\left\{\begin{array}{c}\mathrm{\Δ}f={\mathrm{\Δf}}^{\′}+(K_{3\mathrm{\θ}}+\frac{K_{3\mathrm{\θ}}}{s})({\mathrm{\ω}}_g-{\mathrm{\ω}}_m)\\ \mathrm{\Δ}U={\mathrm{\ΔU}}^{\′}+k_{\mathrm{\δ}}(K_{4\mathrm{\θ}}+\frac{K_{4\mathrm{\θ}}}{s})({\mathrm{\δ}}_g-{\mathrm{\δ}}_m)+\\ +k_p(K_{4P}+\frac{K_{4P}}{s})(P_g-P_m)\end{array}\right.$

The control process of stability controller is as follows:

In system loading disturbance situation, system frequency ω and δ there will be skew, and the deviation of appearance passes through stability controller, obtains micro-capacitance sensor voltage and frequency and the error of external electrical network existence.When carrying out and utilizing micro-capacitance sensor voltage and frequency departure to carry out PI adjustment during net operation, VSG model is entered as positive feedback, along with the frequency moving integrally final elimination micro-capacitance sensor and external electrical network and the voltage deviation of system droop characteristic, namely realize system frequency voltage stabilization and run.

This control module eliminates the voltage detection module in Traditional control, merit angle, angular rate and active power deviation control superposition by PI and obtain new electric voltage frequency and amplitude, add in virtual synchronous generator model and complete synchronism stability control, this stability contorting module idle controlling unit under the state of being incorporated into the power networks has been considered the voltage magnitude deviation eliminating power distribution network and micro-capacitance sensor by merit JIAOSHEN, reaches the purpose of grid-connected requirement.

Visible, the present invention is directed to low pressure micro-capacitance sensor patten transformation, consider to control under micro-capacitance sensor difference operational mode the difference of target, introduce Virtual Torque and damped coefficient and improve the transient characterisitics of the inverter lacking inertia, in conjunction with VSG method and add simulation low-pass filter module and idle integral control module meets two kinds of operational modes different service requirements to DG.

In system loading disturbance situation, system frequency ω and δ there will be skew, and the deviation of appearance passes through stability controller, obtains micro-capacitance sensor voltage and frequency and the error of external electrical network existence.When carrying out and utilizing micro-capacitance sensor voltage and frequency departure to carry out PI adjustment during net operation, VSG model is entered as positive feedback, along with the frequency moving integrally final elimination micro-capacitance sensor and external electrical network and the voltage deviation of system droop characteristic, namely realize system frequency voltage stabilization and run.

This control module eliminates the voltage detection module in Traditional control, merit angle, angular rate and active power deviation control superposition by PI and obtain new electric voltage frequency and amplitude, add in virtual synchronous generator model and complete synchronism stability control, this stability contorting module idle controlling unit under the state of being incorporated into the power networks has been considered the voltage magnitude deviation eliminating power distribution network and micro-capacitance sensor by merit JIAOSHEN, reaches the purpose of grid-connected requirement.

Needing during micro-capacitance sensor island operation state to remove the Reactive Power Control ring that inverter is exported by electrical network, namely during island operation state, during tradition droop control, bulk power grid is supplied to the reactive power of inverter is 0, namely sets Q_g=0, automatically remove the idle controlling unit of outer shroud.The sagging coefficient of tradition droop control is fixing can only carry out proportion adjustment, dynamic property is controlled to adjust by sagging index impacts under micro-capacitance sensor island state, the introducing of the idle storage gain of this method makes parameter can change with situation, improve micro-capacitance sensor inertia, alleviate micro-capacitance sensor and be subject to the temporary impact of load disturbance, be conducive to micro-capacitance sensor island operation state stable, rapid dynamic response speed.

In system loading disturbance situation, system frequency ω and δ there will be skew, and the deviation of appearance passes through stability controller, obtains micro-capacitance sensor voltage and frequency and the error of external electrical network existence.When carrying out and utilizing micro-capacitance sensor voltage and frequency departure to carry out PI adjustment during net operation, VSG model is entered as positive feedback, along with the frequency moving integrally final elimination micro-capacitance sensor and external electrical network and the voltage deviation of system droop characteristic, namely realize system frequency voltage stabilization and run.

The present invention, in order to verify the effectiveness of carried control strategy, has built the micro-capacitance sensor phantom containing two DG, system structure.Simulation system parameters and control parameter are such as shown in table 1-4, and taking reactive power low pass filter time constant herein is 0.04, and switching frequency takes 15kHz, DG power factor and is taken as 0.3,0.2 respectively.Two DG electric voltage frequencies are 50Hz, and voltage magnitude is 310V.

Table 1DG major parameter

Table 2 load parameter

Table 3 line parameter circuit value

Table 4 controls parameter

Simulating, verifying is carried out by load disturbance situation separately below under the conversion of two kinds of operational modes of low pressure micro-capacitance sensor and micro-capacitance sensor island state.

Concrete, planned isolated island is there is from micro-capacitance sensor when can be seen that 1s by Fig. 3 a and Fig. 3 b, before 1s, two DG meet power limitation control, transfer DG active power of output and reactive power respectively 34+j25kVA, 17+j12.5kVA during islet operation to, it is achieved that under island state, carry out reasonable power distribution by measure.From Fig. 3 c and Fig. 3 d it can be seen that during 3.2s micro-capacitance sensor carry out synchronizing cutting-in control, active power and reactive power are transitioned into value and power reference when being incorporated into the power networks, and PCC point voltage and frequency overlap with electrical network port gradually, and during 4s, micro-capacitance sensor re-starts grid-connected.Can be seen that PCC point voltage virtual value is grid-connected and in off-grid process, voltage maximum deviation is 7V, frequency peak excursion, less than 0.2Hz, meets distributed power source Grid-connection standards requirement.

As can be seen from Figure 4: droop control is the comparing result of PCC dot frequency deviation under identical simulated conditions, load 2 put into and in excision process adopt tradition droop control time sudden load change moment generation+0.21Hz, the frequency departure of-0.38Hz, control method lower frequency deviation produces the frequency departure of+0.15Hz ,-0.2Hz respectively in sudden load change moment herein.Can obtain by comparing: the more effective adjustment micro-capacitance sensor frequency of energy in control method sudden load change situation in this paper, produce frequency departure during steady operational status less, be conducive to system run all right.

Claims (6)

1. the self-adaptation control method of a low pressure micro-capacitance sensor pattern, carry out being incorporated into the power networks and the switching of safety and steady between two kinds of operational modes of islet operation in order to realize low pressure micro-capacitance sensor, eliminate transient current when switching and voltge surge, it is characterised in that comprise the following steps:

1) obtain the operation power parameter of low pressure micro-capacitance sensor, build the low pressure micro-capacitance sensor droop control model based on virtual synchronous electromotor；

2) based on, in the low pressure micro-capacitance sensor droop control model of virtual synchronous electromotor, increasing low pass filter between virtual synchronous generator control link and filter inductance, be filtered inductive drop current sample；

3) between virtual synchronous generator control link and reactive power and active power reference value signal, stability controller is increased, between stability controller and reactive power reference qref signal, increase idle storage gain link, the low pressure micro-capacitance sensor droop control model after being improved simultaneously；

4) according to the low pressure micro-capacitance sensor droop control model after improving, low pressure micro-capacitance sensor is carried out pattern switching, eliminate transient current and voltge surge.

2. the self-adaptation control method of a kind of low pressure micro-capacitance sensor pattern according to claim 1, it is characterised in that described virtual synchronous generator control link operation logic is:

$\left\{\begin{array}{c}e={\mathrm{\ω}}_e{M}_f{i}_{e}sin\mathrm{\θ}\\ J\mathrm{\ω}s=\frac{P_T-P_e}{{\mathrm{\ω}}^{*}}+D({\mathrm{\ω}}^{*}-\mathrm{\ω})\\ Q=\frac{3}{2}{M}_f{i}_{e}isin\mathrm{\θ}\end{array}\right.$

Wherein, P_TFor mechanical output, P_eFor electromagnetic power, J is the rotary inertia of rotor, ω^*For reference angular rate, D is permanent damped coefficient, and e is induction electromotive force, M_fFor the maximum induction between Exciting Windings for Transverse Differential Protection and magnetic field winding, i_eFor exciting current, θ is electromotor electrical angle, ω_eFor faradic current angular frequency, ω is reference angle frequency, and i is reference current, and Q is that inverter output is idle, and s is differential coefficient.

3. the self-adaptation control method of a kind of low pressure micro-capacitance sensor pattern according to claim 1, it is characterised in that described step 3) between stability controller and reactive power reference qref signal, increase idle storage gain link after control process be:

$V=V^{*}-m\[Q^{*}-(n_1{Q}_n+\frac{n_2}{s}{Q}_g)\]$

Wherein, V is voltage magnitude reference value, Q_nFor reactive power reference qref, m is sagging coefficient, V^*For by the calculated voltage magnitude of power controller, n₁And n₂When being respectively incorporated into the power networks, micro-capacitance sensor output is idle detects calculated idle gain coefficient, Q with electrical network_nFor inverter output reactive power, Q_gThe reactive power of inverter it is supplied to for electrical network.

4. the self-adaptation control method of a kind of low pressure micro-capacitance sensor pattern according to claim 1, it is characterised in that described step 3) in the mathematical model of stability controller be:

$\left\{\begin{array}{c}\mathrm{\Δ}f={\mathrm{\Δf}}^{\′}+(K_{3\mathrm{\θ}}+\frac{K_{3\mathrm{\θ}}}{s})({\mathrm{\ω}}_g-{\mathrm{\ω}}_m)\\ \mathrm{\Δ}U={\mathrm{\ΔU}}^{\′}+k_{\mathrm{\δ}}(K_{4\mathrm{\θ}}+\frac{K_{4\mathrm{\θ}}}{s})({\mathrm{\δ}}_g-{\mathrm{\δ}}_m)+k_p(K_{4\mathrm{\θ}}+\frac{K_{4\mathrm{\θ}}}{s})(P_g-P_m)\end{array}\right.$

Wherein, wherein, Δ f is the electric voltage frequency after superposition, and Δ f ' is primary voltage frequency, K_3θAnd K_4θFor gain, ω_gFor power distribution network angular rate, ω_mFor micro-capacitance sensor angular rate, Δ U is the amplitude deviation after superposition, and Δ U ' is open width value deviation, k_δAnd k_pIt is respectively U/ δ and U/P gain coefficient, δ_gFor the merit angle of power distribution network output, δ_mFor the merit angle of micro-capacitance sensor output, P_gFor power distribution network output, P_mFor micro-capacitance sensor output.

5. the self-adaptation control method of a kind of low pressure micro-capacitance sensor pattern according to claim 1, it is characterised in that described step 4) in micro-grid connection run time adopt PQ droop control, during islet operation adopt V/f droop control.

6. the self-adaptation control method of a kind of low pressure micro-capacitance sensor pattern according to claim 5, it is characterised in that the active power under low pressure micro-capacitance sensor droop control model grid-connect mode after described improvement and reactive power calculate equation and be:

$\left\{\begin{array}{c}{p}_g=\frac{{\mathrm{EU}}_{pcc}}{Z}\cos \left({\mathrm{\θ}}_{pcc}-\mathrm{\θ}\right)-\frac{U_{pcc}^2}{Z}{\mathrm{cos\θ}}_{pcc}\\ q_g=\frac{{\mathrm{EU}}_{pcc}}{Z}\sin \left({\mathrm{\θ}}_{pcc}-\mathrm{\θ}\right)-\frac{U_{pcc}^2}{Z}{\mathrm{sin\θ}}_{pcc}\end{array}\right.$

Wherein, p_gAnd q_gMeritorious and the reactive power setting value of distributed power source during for low pressure micro-grid connection state, Z is low pressure micro-capacitance sensor line impedance, θ_pccFor PCC point voltage phase angle, θ is inverter output voltage phase angle, and E is inverter output voltage amplitude, U_pccFor PCC point voltage amplitude.