CN104466956A - Load flow calculation method and device for distributed power sources - Google Patents

Abstract

The embodiment of the invention provides a load flow calculation method and device for distributed power sources. The method includes the steps that the connector types of the distributed power sources are determined; the distributed power source adopting an exciting voltage constant synchronous generator connector is equivalent to PV nodes with active power P and voltage V determined; the distributed power source adopting an exciting voltage adjustable synchronous generator connector is equivalent to P-Q(V) nodes with active power P determined and reactive power Q changing along with voltage V; the distributed power source adopting a voltage control type power electronic equipment connector is equivalent to PV nodes with active power P and voltage V determined; the distributed power source adopting a current control type power electronic equipment connector is equivalent to PI nodes with active power P and current I determined; the distributed power source adopting a constant power factor control asynchronous wind driven generator connector is equivalent to PQ nodes; the distributed power source without adopting a constant power factor control asynchronous wind driven generator connector is equivalent to P-Q(V) nodes. A load flow calculation result is more accurate and reliable.

Description

A kind of tidal current computing method of distributed power source and device

Technical field

The present invention relates to the Load flow calculation field of electric power system, particularly relate to a kind of tidal current computing method and device of distributed power source.

Background technology

Load flow calculation is the very important analytical calculation of electric power system, in order to the various problems proposed in Study system planning and operation.So-called Load flow calculation, be exactly the mode of connection of known electrical network and parameter and service conditions, calculating power system mesomeric state runs each busbar voltage, each branch current and power and network loss.For the electric power system run, can judge that whether electrical network busbar voltage, branch current and power is out-of-limit by Load flow calculation, if having out-of-limit, just should take measures, adjust operation mode.For the electric power system planned, by Load flow calculation, foundation can be provided for selecting mains supply scheme and electric equipment.Load flow calculation can also provide initial data for relaying protection and the fixed whole calculating of automatics, electric power system fault calculating and stability Calculation etc.

When considering via net loss, when distributed power source capacity one timing, in power distribution network in any one section of branch road, the grid-connected position of distributed power source is the closer to load, network loss is less, in the legacy network power flow algorithm of PQ node and PV node, in hypothetical network, distributed power source is installed in the position near load point, because load point in Load flow calculation is PQ node, conveniently calculate, the load of distributed power source and place node is considered as a PV node, thus power distribution network is equivalent to one only containing balance node.

But, with regard to actual conditions, the interface shape that the grid-connected employing of different distributed power sources is different, interface shape has synchronous generator, asynchronous generator and power electronic equipment three class, wherein, power electronic equipment interface mainly comprises rectifier, current transformer, inverter, and the system comprising distributed power source with distinct interface form is all equivalent to identical power flow algorithm, will have influence on the accuracy of calculation of tidal current.

Summary of the invention

In view of this, the embodiment of the present invention provides a kind of tidal current computing method and device of distributed power source, to solve in prior art, the system comprising distributed power source with distinct interface form is all equivalent to identical power flow algorithm, has influence on the problem of the accuracy of calculation of tidal current.

For achieving the above object, the embodiment of the present invention provides following technical scheme:

A tidal current computing method for distributed power source, comprising:

Determine the interface shape of distributed power source;

The PV node being equivalent to active-power P and voltage V by adopting the distributed power source of exciting voltage constant synchronization generator interface and determining;

Be equivalent to P by adopting the distributed power source of exciting voltage adjustable synchronous generator interface to determine, reactive power Q is P-Q (V) node of change with V change;

The distributed power source of employing voltage-controlled type power electronic equipment interface is equivalent to the PV node that P and V determines;

The distributed power source mouth adopting current-control type power electronic equipment to connect is equivalent to the PI node that P and electric current I are determined;

PQ node is equivalent to by adopting the distributed power source of invariable power factor controlling asynchronous wind driven generator interface;

P-Q (V) node is equivalent to by not adopting the distributed power source of invariable power factor controlling asynchronous wind driven generator interface.

Wherein, Q in described P-Q (V) node _gwith the pass of V be:

$Q_G=\frac{V^3}{x_m}+\frac{V^2-\sqrt{V^4-4P^2{x}^2}}{2x},$

Wherein, x is stator reactance and rotor reactance sum, x _mfor field excitation branch line reactance.

Wherein, Q in described PI node _ewith the pass of I be:

$Q_E=\sqrt{I^2{V}^2-P^2}.$

Wherein, the described distributed power source of invariable power factor controlling asynchronous wind driven generator interface that do not adopt comprises: asynchronous wind driven generator,

The power P of described asynchronous wind driven generator _mfor:

$P_m=\frac{1}{2}\mathrm{\ρ}{\mathrm{AV}}^3{C}_p,$

Wherein, ρ is atmospheric density, unit km/m3; A is the sectional area of wind power generator impeller perpendicular to wind speed, and unit is m2; V is wind speed, and unit is m/s; C _pfor the power coefficient of generator.

Wherein, described wind speed V is:

$V=V_r{\left(\frac{h}{h_r}\right)}^{\mathrm{\γ}},$

Wherein, V _rby meteorological observatory's anemometer tower is surveyed wind speed, h is wind power generator impeller height, h _rfor anemometer tower height, γ is trimming coefficient.

Wherein, the distributed power source of voltage-controlled type power electronic equipment interface is adopted to comprise: photovoltaic generator,

The recommended current I of described photovoltaic generator _pVwith optimum operating voltage V _pVfor:

$\left\{\begin{array}{c}{I}_{\mathrm{PV}}=I_{\mathrm{SC}}\{1-C_1[\exp \left(\frac{V_{\mathrm{PV}}-\mathrm{\ΔV}}{C_2{\mathrm{SV}}_{\mathrm{OC}}}\right)-1\left]\right\}+\mathrm{\ΔI}\\ C_1=(1-I_{\mathrm{mp}}/I_{\mathrm{SC}})\exp [-V_{\mathrm{mp}}/\left(C_2{V}_{\mathrm{OC}}\right)]\\ C_2=\frac{V_{\mathrm{mp}}/V_{\mathrm{OC}}-1}{\ln (1-I_{\mathrm{mp}}/I_{\mathrm{SC}})}\\ V_{\mathrm{PV}}=V_{\mathrm{mp}}[1+0.0539\lg \left(\frac{H_{\mathrm{\θ}}}{H_t}\right)]+{\mathrm{\β}}_o\mathrm{\ΔT}\\ \mathrm{\ΔV}=V_{\mathrm{PV}}-V_{\mathrm{mp}}\\ \mathrm{\ΔT}=T_A+0.02H_{\mathrm{\θ}}-T_t\\ \mathrm{\ΔI}=\left(\frac{H_{\mathrm{\θ}}}{H_t}\right)\mathrm{\ΔT}+(\frac{H_{\mathrm{\θ}}}{H_t}-1)I_{\mathrm{SC}}\end{array}\right.,$

Wherein, I _sCfor the short circuit current of light generator, V _oCfor the open circuit voltage of photovoltaic generator, I _mpfor photovoltaic generator maximum power point electric current, V _mpfor photovoltaic generation and maximum power point voltage, H _tfor standard intensity of illumination, T is normal temperature, T _afor ambient temperature, β _ofor photovoltaic battery panel angle of inclination, H _θfor the solar radiation quantity on photovoltaic battery panel.

Wherein, described photovoltaic generator power output P _pVfor:

P _PV＝V _PVI _PV，

Wherein, I _pVfor recommended current and V _pVfor optimum operating voltage.

Wherein, described solar radiation quantity H _θfor mean value or the instantaneous value of meteorological observatory's observation data.

Wherein, described standard intensity of illumination is 1000W/m2, and described normal temperature is 25 DEG C.

A Load flow calculation device for distributed power source, comprising: determination module, the first processing module, the second processing module, the 3rd processing module, the 4th processing module, the 5th processing module and the 6th processing module; Wherein,

Described determination module, for determining the interface shape of distributed power source;

Described first processing module, for the PV node that will the distributed power source of exciting voltage constant synchronization generator interface adopted to be equivalent to active-power P and voltage V determine;

Described second processing module, for determining adopting the distributed power source of exciting voltage adjustable synchronous generator interface to be equivalent to P, reactive power Q is P-Q (V) node of change with V change;

Described 3rd processing module, for being equivalent to the PV node that P and V determines by the distributed power source of employing voltage-controlled type power electronic equipment interface;

Described 4th processing module, for being equivalent to the PI node that P and electric current I are determined by the distributed power source mouth adopting current-control type power electronic equipment to connect;

Described 5th processing module, for adopting the distributed power source of invariable power factor controlling asynchronous wind driven generator interface to be equivalent to PQ node;

Described 6th processing module, for not adopting the distributed power source of invariable power factor controlling asynchronous wind driven generator interface to be equivalent to P-Q (V) node.

Based on technique scheme, the tidal current computing method of the distributed power source that the embodiment of the present invention provides and device, after determining the interface shape of distributed power source, the PV node being equivalent to active-power P and voltage V by adopting the distributed power source of exciting voltage constant synchronization generator interface and determining, be equivalent to P by adopting the distributed power source of exciting voltage adjustable synchronous generator interface to determine, reactive power Q is P-Q (V) node of change with V change, the distributed power source of employing voltage-controlled type power electronic equipment interface is equivalent to the PV node that P and V determines, the distributed power source mouth adopting current-control type power electronic equipment to connect is equivalent to the PI node that P and electric current I are determined, PQ node is equivalent to by adopting the distributed power source of invariable power factor controlling asynchronous wind driven generator interface, P-Q (V) node is equivalent to by not adopting the distributed power source of invariable power factor controlling asynchronous wind driven generator interface.Because, the interface shape that the grid-connected employing of different distributed power sources is different, mainly comprise synchronous generator interface, asynchronous generator interface and power electronic equipment interface three class, wherein, synchronous generator interface comprises the constant and adjustable two kinds of modes of exciting voltage of exciting voltage, power electronic equipment interface bag voltage-controlled type and current-control type, asynchronous wind driven generator interface comprises employing constant power factor and controls and do not adopt constant power factor to control two kinds, therefore, corresponding power flow algorithm is equivalent to by using the dissimilar distributed power source of distinct interface form, namely to being equivalent to PV node, PQ node, the distributed power source of PI node and P-Q (V) node uses PV nodal analysis method respectively, PQ nodal analysis method, PI nodal analysis method and P-Q (V) nodal analysis method carry out Load flow calculation, make calculation of tidal current more accurately and reliably.

Accompanying drawing explanation

In order to be illustrated more clearly in the embodiment of the present invention or technical scheme of the prior art, be briefly described to the accompanying drawing used required in embodiment or description of the prior art below, apparently, accompanying drawing in the following describes is only embodiments of the invention, for those of ordinary skill in the art, under the prerequisite not paying creative work, other accompanying drawing can also be obtained according to the accompanying drawing provided.

The flow chart of the system load flow computational methods that Fig. 1 provides for the embodiment of the present invention;

The system block diagram of the system load flow calculation element that Fig. 2 provides for the embodiment of the present invention.

Embodiment

Below in conjunction with the accompanying drawing in the embodiment of the present invention, be clearly and completely described the technical scheme in the embodiment of the present invention, obviously, described embodiment is only the present invention's part embodiment, instead of whole embodiments.Based on the embodiment in the present invention, those of ordinary skill in the art, not making the every other embodiment obtained under creative work prerequisite, belong to the scope of protection of the invention.

The flow chart of the system load flow computational methods of the distributed power source that Fig. 1 provides for the embodiment of the present invention, by using the dissimilar distributed power source of distinct interface form to be equivalent to corresponding power flow algorithm, makes calculation of tidal current more accurately and reliably; With reference to Fig. 1, the system load flow computational methods of this distributed power source can comprise:

Step S100: the interface shape determining distributed power source;

Emerging distributed generation technology mainly comprises the technology such as photovoltaic cell, wind power generation, biomass power generation, tidal power generation of small size gas turbine, miniature gas turbine, fuel cell technology and the employing regenerative resource adopting fossil fuel.

The interface shape that the grid-connected employing of different distributed power sources is different, mainly comprises synchronous generator, asynchronous generator and power electronic equipment three class.Power electronic equipment interface mainly comprises rectifier, current transformer, inverter, and along with power electronic technology and the development controlling new technology, inversion transformation technique is developed rapidly.Be connected with electrical network by converters, simple to operate, and there is the ability regulating reactive power to exert oneself, the stability of system cloud gray model can be improved.Common distributed power source capacity and interface type as shown in table 1:

The common distributed power source capacity of table 1 and interface type

Step S110: the PV nodal analysis method being equivalent to active-power P and voltage V by adopting the distributed power source of exciting voltage constant synchronization generator interface and determining;

Step S120: be equivalent to P by adopting the distributed power source of exciting voltage adjustable synchronous generator interface and determine, reactive power Q is P-Q (V) nodal analysis method of change with V change;

Synchronous generator interface comprises the constant and adjustable two kinds of modes of exciting voltage of exciting voltage, and the former can regard as PV node and carry out Load flow calculation, and the latter regards as P-Q (V) node.This class interface uses less, as geothermal energy distributed power source etc.;

Step S130: the distributed power source of employing voltage-controlled type power electronic equipment interface is equivalent to the PV nodal analysis method that P and V determines;

Step S140: the distributed power source mouth adopting current-control type power electronic equipment to connect is equivalent to the PI nodal analysis method that P and electric current I are determined;

Power electronic equipment interface comprises multiple current transformer, and node general equivalence in voltage-controlled type device place becomes PV node; Node general equivalence in current-control type device place becomes PI node, and this interface uses extensively, comprises photovoltaic generation, small size gas turbine, fuel cell, synchronous speed change wind-driven generator etc.

Step S150: be equivalent to PQ nodal analysis method by adopting the distributed power source of invariable power factor controlling asynchronous wind driven generator interface;

Step S160: be equivalent to P-Q (V) nodal analysis method by not adopting the distributed power source of invariable power factor controlling asynchronous wind driven generator interface.

Asynchronous wind driven generator interface controls then can be equivalent to PQ node according to constant power factor, otherwise can equivalence become P-Q (V) node to process.

Based on technique scheme, the system load flow computational methods of the distributed power source that the embodiment of the present invention provides and device, after determining the interface shape of distributed power source, the PV node being equivalent to active-power P and voltage V by adopting the distributed power source of exciting voltage constant synchronization generator interface and determining, be equivalent to P by adopting the distributed power source of exciting voltage adjustable synchronous generator interface to determine, reactive power Q is P-Q (V) node of change with V change, the distributed power source of employing voltage-controlled type power electronic equipment interface is equivalent to the PV node that P and V determines, the distributed power source mouth adopting current-control type power electronic equipment to connect is equivalent to the PI node that P and electric current I are determined, PQ node is equivalent to by adopting the distributed power source of invariable power factor controlling asynchronous wind driven generator interface, P-Q (V) node is equivalent to by not adopting the distributed power source of invariable power factor controlling asynchronous wind driven generator interface.Because, the interface shape that the grid-connected employing of different distributed power sources is different, mainly comprise synchronous generator interface, asynchronous generator interface and power electronic equipment interface three class, wherein, synchronous generator interface comprises the constant and adjustable two kinds of modes of exciting voltage of exciting voltage, power electronic equipment interface bag voltage-controlled type and current-control type, asynchronous wind driven generator interface comprises employing constant power factor and controls and do not adopt constant power factor to control two kinds, therefore, corresponding power flow algorithm is equivalent to by using the dissimilar distributed power source of distinct interface form, make calculation of tidal current more accurately and reliably.

Optionally, Q in P-Q (V) node _gwith the relation of V can be:

$Q_G=\frac{V^3}{x_m}+\frac{V^2-\sqrt{V^4-4P^2{x}^2}}{2x},$

Wherein, x is stator reactance and rotor reactance sum, x _mfor field excitation branch line reactance

Optionally, Q in PI node _ewith the relation of I can be:

$Q_E=\sqrt{I^2{V}^2-P^2}.$

Optionally, the power P of the asynchronous wind driven generator in the distributed power source of invariable power factor controlling asynchronous wind driven generator interface is not adopted _mcan be:

$P_m=\frac{1}{2}\mathrm{\ρ}{\mathrm{AV}}^3{C}_p,$

Wherein, ρ is atmospheric density, unit km/m3; A is the sectional area of wind power generator impeller perpendicular to wind speed, and unit is m2; V is wind speed, and unit is m/s; C _pfor the power coefficient of generator.

Wherein, wind speed V can be:

$V=V_r{\left(\frac{h}{h_r}\right)}^{\mathrm{\γ}},$

Wherein, V _rby meteorological observatory's anemometer tower is surveyed wind speed, h is wind power generator impeller height, h _rfor anemometer tower height, γ is trimming coefficient.

Optionally, trimming coefficient gamma can value be 1/7.

The recommended current I of the photovoltaic generator of the distributed power source of optional employing voltage-controlled type power electronic equipment interface _pVwith optimum operating voltage V _pVcan be:

$\left\{\begin{array}{c}{I}_{\mathrm{PV}}=I_{\mathrm{SC}}\{1-C_1[\exp \left(\frac{V_{\mathrm{PV}}-\mathrm{\ΔV}}{C_2{\mathrm{SV}}_{\mathrm{OC}}}\right)-1\left]\right\}+\mathrm{\ΔI}\\ C_1=(1-I_{\mathrm{mp}}/I_{\mathrm{SC}})\exp [-V_{\mathrm{mp}}/\left(C_2{V}_{\mathrm{OC}}\right)]\\ C_2=\frac{V_{\mathrm{mp}}/V_{\mathrm{OC}}-1}{\ln (1-I_{\mathrm{mp}}/I_{\mathrm{SC}})}\\ V_{\mathrm{PV}}=V_{\mathrm{mp}}[1+0.0539\lg \left(\frac{H_{\mathrm{\θ}}}{H_t}\right)]+{\mathrm{\β}}_o\mathrm{\ΔT}\\ \mathrm{\ΔV}=V_{\mathrm{PV}}-V_{\mathrm{mp}}\\ \mathrm{\ΔT}=T_A+0.02H_{\mathrm{\θ}}-T_t\\ \mathrm{\ΔI}=\left(\frac{H_{\mathrm{\θ}}}{H_t}\right)\mathrm{\ΔT}+(\frac{H_{\mathrm{\θ}}}{H_t}-1)I_{\mathrm{SC}}\end{array}\right.,$

Wherein, I _sCfor the short circuit current of light generator, V _oCfor the open circuit voltage of photovoltaic generator, I _mpfor photovoltaic generator maximum power point electric current, V _mpfor photovoltaic generation and maximum power point voltage, H _tfor standard intensity of illumination, T is normal temperature, T _afor ambient temperature, β _ofor photovoltaic battery panel angle of inclination, H _θfor the solar radiation quantity on photovoltaic battery panel.

Optionally, photovoltaic generator power output P _pVcan be:

P _PV＝V _PVI _PV，

Wherein, I _pVfor recommended current and V _pVfor optimum operating voltage.

Optionally, solar radiation quantity H _θcan be mean value or the instantaneous value of meteorological observatory's observation data.

Optionally, standard intensity of illumination can be 1000W/m2, and described normal temperature can be 25 DEG C.

The tidal current computing method of the distributed power source that the embodiment of the present invention provides, the dissimilar distributed power source of distinct interface form is used to be equivalent to corresponding power flow algorithm, namely use PV nodal analysis method, PQ nodal analysis method, PI nodal analysis method and P-Q (V) nodal analysis method to carry out Load flow calculation respectively to the distributed power source being equivalent to PV node, PQ node, PI node and P-Q (V) node, make calculation of tidal current more accurately and reliably.

Be introduced the Load flow calculation device of the distributed power source that the embodiment of the present invention provides below, the Load flow calculation device of distributed power source described below can mutual corresponding reference with the tidal current computing method of above-described distributed power source.

The system block diagram of the Load flow calculation device of the distributed power source that Fig. 2 provides for the embodiment of the present invention, with reference to Fig. 2, the Load flow calculation device of this distributed power source can comprise: determination module 100, first processing module 200, second processing module 300, the 3rd processing module 400, the 4th processing module 500, the 5th processing module 600 and the 6th processing module 700; Wherein,

Determination module 100, for determining the interface shape of distributed power source;

First processing module 200, for the PV node that will the distributed power source of exciting voltage constant synchronization generator interface adopted to be equivalent to active-power P and voltage V determine;

Second processing module 300, for determining adopting the distributed power source of exciting voltage adjustable synchronous generator interface to be equivalent to P, reactive power Q is P-Q (V) node of change with V change;

3rd processing module 400, for being equivalent to the PV node that P and V determines by the distributed power source of employing voltage-controlled type power electronic equipment interface;

4th processing module 500, for being equivalent to the PI node that P and electric current I are determined by the distributed power source mouth adopting current-control type power electronic equipment to connect;

5th processing module 600, for adopting the distributed power source of invariable power factor controlling asynchronous wind driven generator interface to be equivalent to PQ node;

6th processing module 700, for not adopting the distributed power source of invariable power factor controlling asynchronous wind driven generator interface to be equivalent to P-Q (V) node.

The Load flow calculation device of the distributed power source that the embodiment of the present invention provides, the dissimilar distributed power source of distinct interface form is used to be equivalent to corresponding power flow algorithm, namely use PV nodal analysis method, PQ nodal analysis method, PI nodal analysis method and P-Q (V) nodal analysis method to carry out Load flow calculation respectively to the distributed power source being equivalent to PV node, PQ node, PI node and P-Q (V) node, make calculation of tidal current more accurately and reliably.

In this specification, each embodiment adopts the mode of going forward one by one to describe, and what each embodiment stressed is the difference with other embodiments, between each embodiment identical similar portion mutually see.For device disclosed in embodiment, because it corresponds to the method disclosed in Example, so description is fairly simple, relevant part illustrates see method part.

Professional can also recognize further, in conjunction with unit and the algorithm steps of each example of embodiment disclosed herein description, can realize with electronic hardware, computer software or the combination of the two, in order to the interchangeability of hardware and software is clearly described, generally describe composition and the step of each example in the above description according to function.These functions perform with hardware or software mode actually, depend on application-specific and the design constraint of technical scheme.Professional and technical personnel can use distinct methods to realize described function to each specifically should being used for, but this realization should not thought and exceeds scope of the present invention.

The software module that the method described in conjunction with embodiment disclosed herein or the step of algorithm can directly use hardware, processor to perform, or the combination of the two is implemented.Software module can be placed in the storage medium of other form any known in random asccess memory (RAM), internal memory, read-only memory (ROM), electrically programmable ROM, electrically erasable ROM, register, hard disk, moveable magnetic disc, CD-ROM or technical field.

To the above-mentioned explanation of the disclosed embodiments, professional and technical personnel in the field are realized or uses the present invention.To be apparent for those skilled in the art to the multiple amendment of these embodiments, General Principle as defined herein can without departing from the spirit or scope of the present invention, realize in other embodiments.Therefore, the present invention can not be restricted to these embodiments shown in this article, but will meet the widest scope consistent with principle disclosed herein and features of novelty.

Claims (10)

1. a tidal current computing method for distributed power source, is characterized in that, comprising:

Determine the interface shape of distributed power source;

The PV node being equivalent to active-power P and voltage V by adopting the distributed power source of exciting voltage constant synchronization generator interface and determining;

Be equivalent to P by adopting the distributed power source of exciting voltage adjustable synchronous generator interface to determine, reactive power Q is P-Q (V) node of change with V change;

The distributed power source of employing voltage-controlled type power electronic equipment interface is equivalent to the PV node that P and V determines;

The distributed power source mouth adopting current-control type power electronic equipment to connect is equivalent to the PI node that P and electric current I are determined;

PQ node is equivalent to by adopting the distributed power source of invariable power factor controlling asynchronous wind driven generator interface;

P-Q (V) node is equivalent to by not adopting the distributed power source of invariable power factor controlling asynchronous wind driven generator interface.

2. tidal current computing method according to claim 1, is characterized in that, Q in described P-Q (V) node _gwith the pass of V be:

$Q_G=\frac{V^2}{x_m}+\frac{V^2-\sqrt{V^4-4P^2{x}^2}}{2x},$

Wherein, x is stator reactance and rotor reactance sum, x _mfor field excitation branch line reactance.

3. tidal current computing method according to claim 1, is characterized in that, Q in described PI node _ewith the pass of I be:

$Q_E=\sqrt{I^2{V}^2-P^2}.$

4. tidal current computing method according to claim 1, is characterized in that, the described distributed power source of invariable power factor controlling asynchronous wind driven generator interface that do not adopt comprises: asynchronous wind driven generator,

The power P of described asynchronous wind driven generator _mfor:

$P_m=\frac{1}{2}\mathrm{\ρ}{\mathrm{AV}}^3{C}_p,$

Wherein, ρ is atmospheric density, unit km/m3; A is the sectional area of wind power generator impeller perpendicular to wind speed, and unit is m2; V is wind speed, and unit is m/s; C _pfor the power coefficient of generator.

5. want the tidal current computing method described in 4 according to right, it is characterized in that, described wind speed V is:

$V=V_r{\left(\frac{h}{h_r}\right)}^{\mathrm{\γ}},$

Wherein, V _rby meteorological observatory's anemometer tower is surveyed wind speed, h is wind power generator impeller height, h _rfor anemometer tower height, γ is trimming coefficient.

6. want the tidal current computing method described in 1 according to right, it is characterized in that, adopt the distributed power source of voltage-controlled type power electronic equipment interface to comprise: photovoltaic generator,

The recommended current I of described photovoltaic generator _pVwith optimum operating voltage V _pVfor:

$\left\{\begin{array}{c}{I}_{\mathrm{PV}}=I_{\mathrm{SC}}\{1-C_1[\exp \left(\frac{V_{\mathrm{PV}}-\mathrm{\ΔV}}{C_2{V}_{\mathrm{OC}}}\right)-1\left]\right\}+\mathrm{\ΔI}\\ C_1=(1-I_{\mathrm{mp}}/I_{\mathrm{SC}})\exp [-V_{\mathrm{mp}}/\left(C_2{V}_{\mathrm{OC}}\right)]\\ C_2=\frac{V_{\mathrm{mp}}/V_{\mathrm{OC}}-1}{\ln (1-I_{\mathrm{mp}}/I_{\mathrm{SC}})}\\ V_{\mathrm{PV}}=V_{\mathrm{mp}}[1+0.05391g\left(\frac{H_{\mathrm{\θ}}}{H_t}\right)]+{\mathrm{\β}}_o\mathrm{\ΔT}\\ \mathrm{\ΔV}=V_{\mathrm{PV}}-V_{\mathrm{mp}}\\ \mathrm{\ΔT}=T_A+0.02H_{\mathrm{\θ}}-T_t\\ \mathrm{\ΔI}=\left(\frac{H_{\mathrm{\θ}}}{H_t}\right)\mathrm{\ΔT}+(\frac{H_{\mathrm{\θ}}}{H_t}-1)I_{\mathrm{SC}}\end{array}\right.,$

Wherein, I _sCfor the short circuit current of light generator, V _oCfor the open circuit voltage of photovoltaic generator, I _mpfor photovoltaic generator maximum power point electric current, V _mpfor photovoltaic generation and maximum power point voltage, H _tfor standard intensity of illumination, T is normal temperature, T _afor ambient temperature, β _ofor photovoltaic battery panel angle of inclination, H _θfor the solar radiation quantity on photovoltaic battery panel.

7. tidal current computing method according to claim 6, is characterized in that, described photovoltaic generator power output P _pVfor:

P _PV＝V _PVI _PV，

Wherein, I _pVfor recommended current and V _pVfor optimum operating voltage.

8. tidal current computing method according to claim 6, is characterized in that, described solar radiation quantity H _θfor mean value or the instantaneous value of meteorological observatory's observation data.

9. tidal current computing method according to claim 6, is characterized in that, described standard intensity of illumination is 1000W/m2, and described normal temperature is 25 DEG C.

10. a Load flow calculation device for distributed power source, is characterized in that, comprising: determination module, the first processing module, the second processing module, the 3rd processing module, the 4th processing module, the 5th processing module and the 6th processing module; Wherein,

Described determination module, for determining the interface shape of distributed power source;

Described first processing module, for the PV node that will the distributed power source of exciting voltage constant synchronization generator interface adopted to be equivalent to active-power P and voltage V determine;

Described second processing module, for determining adopting the distributed power source of exciting voltage adjustable synchronous generator interface to be equivalent to P, reactive power Q is P-Q (V) node of change with V change;

Described 3rd processing module, for being equivalent to the PV node that P and V determines by the distributed power source of employing voltage-controlled type power electronic equipment interface;

Described 4th processing module, for being equivalent to the PI node that P and electric current I are determined by the distributed power source mouth adopting current-control type power electronic equipment to connect;

Described 5th processing module, for adopting the distributed power source of invariable power factor controlling asynchronous wind driven generator interface to be equivalent to PQ node;

Described 6th processing module, for not adopting the distributed power source of invariable power factor controlling asynchronous wind driven generator interface to be equivalent to P-Q (V) node.