CN104348180A - Distributed power supply grid-connected point and access mode selection method - Google Patents

Abstract

The invention discloses a distributed power supply grid-connected point and access mode selection method. The method includes the steps of: 1) determining power generation characteristics of distributed power supplies which need grid connection; 2) knowing the situation of a power grid of an area where the distributed power supplies are located, making statistics of capacity and load of a single main transformer of a public transformer substation of each voltage class, and calculating a weighted average of capacity of the main transformer of each voltage class; 3) preliminarily selecting a voltage class of grid connection according to power generation capacity of the distributed power supplies; 4) determining an access mode of the distributed power supplies; and 5) determining an access point of the distributed power supplies. By adoption of the distributed power supply grid-connected point and access mode selection method provided by the invention, influence of access on safe and stable operation of the power grid can be reduced to the greatest extent on the premise of ensuring effective access of the distributed power supplies to the power grid.

Description

Distributed power source site and access way choosing method

Technical field

The present invention relates to for electrical domain, particularly a kind of distributed power source site and access way choosing method.

Background technology

Along with the fast development of wind power generation, photovoltaic generation, biomass power generation and other all kinds of energy-saving environment protection type power, its generating proportion is in the situation that rises year by year.Wind power generation, photovoltaic generation, biomass power generation and the general capacity of other all kinds of generation of electricity by new energy are all smaller, and the form of power supply is incorporated to low-voltage-grade electrical network in a distributed manner.From traditional Large Copacity power supply, to be directly incorporated into voltage levels electrical network different, and distributed power source form is varied, the characteristic that all kinds power supply has himself to run; And distributed power source is near user side, this will change the traditional radial electric power-feeding structure of electric power system, has an impact to safe and stable operation, the quality of power supply, meritorious/idle control, the protection of power distribution network and the aspect such as to communicate.

Above-mentioned impact brings brand-new challenge by running enterprise to electrical network especially power distribution network, how under guaranteeing that distributed power source effectively accesses the prerequisite of electrical network, at utmost reducing its impact of access on power network safety operation, is the actual difficult point urgently to be resolved hurrily of current engineering.

Summary of the invention

The object of the present invention is to provide a kind of can for the feature of distributed power source generating, in conjunction with urban distribution network grid structure, the distributed power source considering distributed power source access region electric network influencing factor site and access way choosing method.

To achieve these goals, technical scheme of the present invention is as follows:

A kind of distributed power source site and access way choosing method, comprise the following steps:

1) the generating feature needing grid-connected distributed power source is determined;

2) understand the grid condition of distributed power source region, add up separate unit main transformer capacity and the load of each electric pressure public transformer substation, calculate each electric pressure main transformer capacity weighted average;

3) its grid-connected electric pressure is tentatively chosen according to the generate output of distributed power source;

4) access way of distributed power source is determined;

5) access point of distributed power source is determined.

Preferably, the distributed power source in step 1) comprises synchronous machine, asynchronous machine and inverter type distributed power source.

Preferably, step 2) in calculate the computing formula of each electric pressure main transformer capacity weighted average as follows,

$\stackrel{\‾}{T_i}=\frac{\underset{j=1}{\overset{\mathrm{ni}}{\mathrm{\Σ}}}{T}_{\mathrm{ij}}\×\mathrm{if}((L_{\mathrm{ij}}-L)>0)}{\underset{j=1}{\overset{\mathrm{ni}}{\mathrm{\Σ}}}\mathrm{if}((L_{\mathrm{ij}}-L)>0)}---\left(a\right)$

Wherein,

-distributed power source location can be accessed by the weighted average of the main transformer capacity that voltage is " i " kV;

I-electric pressure, generally can get 380V, 10kV, 35kV etc.;

Ni-distributed power source location has the main transformer quantity that voltage is " i " kV;

T _ij-distributed power source location has the capacity of the jth main transformer that voltage is " i " kV electric pressure;

L _ij-distributed power source location have voltage for " i " kV electric pressure a jth main transformer load factor;

L-constant, is the threshold value of main transformer load factor, can chooses according to grid condition;

F ((L _ij-L) >0)-judging weight, it is as (L _ij-L) >0 duration is 1, otherwise value is 0.

Preferably, the formula choosing its grid-connected electric pressure in step 3) is as follows,

$V_{\mathrm{DERi}}=\mathrm{if}(C_{\mathrm{DER}}<\frac{\stackrel{\&OverBar;}{T_i}}{N_T})---\left(b\right)$

Wherein,

In above formula,

-distributed power source location voltage is the weighted average of the main transformer capacity of " i " kV;

I-electric pressure, generally can get 380V, 10kV, 35kV etc.;

N _t-one be greater than 1 constant;

C _dERthe installed capacity of-this distributed power source;

-one numerical value, when duration is 1, otherwise is 0;

V _dERi-distributed power source access electric pressure tentatively choose flag bit, when its value is 1, expression can be incorporated to voltage for the electrical network of " i " kV, generally gets two electric pressures.

Preferably, in step 4), the determination formula of the access way of distributed power source is,

$F_{\mathrm{DER}}=\mathrm{if}(C_{\mathrm{DER}}<\frac{C_L}{N_l})---\left(c\right)$

Wherein,

C _lthe transmission capacity of-grid-connected circuit;

N _l-one be greater than 1 constant;

F _dERthe access way of-distributed power source, its value is that 1 expression can adopt non-access via telephone line, and its value is that 0 expression adopts access via telephone line mode.

Preferably, in step 5), the determining step of the access point of distributed power source is as follows,

If F _dER=0, choose V _dERimain transformer in electric pressure corresponding to flag bit, carries out a weight computing according to formula (d), then sorts, get D _ij" i " kV electric pressure side of the main transformer corresponding to minimum in non-vanishing numerical value is as the access point of this distributed power source;

$D_{\mathrm{ij}}=\mathrm{if}(m_{\mathrm{ij}}<m_{\max \mathrm{ij}})(\frac{C_{\mathrm{DER}}+\underset{k=1}{\overset{\mathrm{nij}}{\mathrm{\&Sigma;}}}{C}_{\mathrm{DERk}}}{C_{\mathrm{Tij}}}+\frac{d_{\mathrm{ij}}}{d_i})---\left(d\right)$

Wherein,

M _maxijthe voltage an of-present situation jth main transformer is the quantity of " i " kV outgoing line interval;

M _ijthe voltage an of-present situation jth main transformer is the quantity of outlet in " i " kV outgoing line interval;

N _ijthe voltage an of-present situation jth main transformer is the quantity that " i " kV side joint enters distributed power source;

C _dERkthe voltage an of-present situation jth main transformer is the installed capacity of " i " kV side kth distributed power source;

D _ij-this distributed power source is " i " kV side grid power source linear distance to the voltage of a jth main transformer;

D _i-place power supply enterprise is the upper limit of the reasonable power supply distance of regulation of " i " kV electric pressure about voltage;

If F _dER=1, then this distributed power source accesses the circuit that voltage is " i " kV nearby;

Although if V _dERi=1, but " i " kV electrical network is discontented is enough to determined condition, then need the upper electric pressure net forwarding " i " kV electrical network to carry out and the choosing of site and access way, until determine suitable and site and access way.

Adopt distributed power source of the present invention and site and access way choosing method generate electricity for distributed power source feature, in conjunction with urban distribution network grid structure, propose to consider distributed power source access region electric network influencing factor, under guaranteeing that distributed power source effectively accesses the prerequisite of electrical network, at utmost reduce its impact of access on power network safety operation.

Embodiment

Distributed power source of the present invention site and access way choosing method, comprise the following steps:

1) determine the generating feature needing grid-connected distributed power source, wherein, distributed power source comprises synchronous machine, asynchronous machine and inverter type distributed power source.

2) grid condition of distributed power source region is understood, add up separate unit main transformer capacity and the load of each electric pressure public transformer substation, calculate each electric pressure main transformer capacity weighted average, wherein, the computing formula calculating each electric pressure main transformer capacity weighted average is as follows

$\stackrel{\&OverBar;}{T_i}=\frac{\underset{j=1}{\overset{\mathrm{ni}}{\mathrm{\&Sigma;}}}{T}_{\mathrm{ij}}\&times;\mathrm{if}((L_{\mathrm{ij}}-L)>0)}{\underset{j=1}{\overset{\mathrm{ni}}{\mathrm{\&Sigma;}}}\mathrm{if}((L_{\mathrm{ij}}-L)>0)}---\left(a\right)$

In above formula,

-distributed power source location can be accessed by the weighted average of the main transformer capacity that voltage is " i " kV;

I-electric pressure, generally can get 380V, 10kV, 35kV etc.;

Ni-distributed power source location has the main transformer quantity that voltage is " i " kV;

T _ij-distributed power source location has the capacity of the jth main transformer that voltage is " i " kV electric pressure;

L _ij-distributed power source location have voltage for " i " kV electric pressure a jth main transformer load factor;

L-constant, is the threshold value of main transformer load factor, can chooses according to grid condition;

F ((L _ij-L) >0)-judging weight, it is as (L _ij-L) >0 duration is 1, otherwise value is 0.

3) tentatively choose its grid-connected electric pressure according to the generate output of distributed power source, wherein, the formula choosing its grid-connected electric pressure is as follows,

$V_{\mathrm{DERi}}=\mathrm{if}(C_{\mathrm{DER}}<\frac{\stackrel{\&OverBar;}{T_i}}{N_T})---\left(b\right)$

In above formula,

-distributed power source location voltage is the weighted average of the main transformer capacity of " i " kV;

I-electric pressure, generally can get 380V, 10kV, 35kV etc.;

N _t-one be greater than 1 constant;

C _dERthe installed capacity of-this distributed power source;

-one numerical value, when duration is 1, otherwise is 0;

V _dERi-distributed power source access electric pressure tentatively choose flag bit, when its value is 1, expression can be incorporated to voltage for the electrical network of " i " kV, generally gets two electric pressures.

4) determine the access way of distributed power source, wherein, the determination formula of the access way of distributed power source is,

$F_{\mathrm{DER}}=\mathrm{if}(C_{\mathrm{DER}}<\frac{C_L}{N_l})---\left(c\right)$

In above formula,

C _lthe transmission capacity of-grid-connected circuit;

N _l-one be greater than 1 constant;

F _dERthe access way of-distributed power source, its value is that 1 expression can adopt non-access via telephone line, and its value is that 0 expression adopts access via telephone line mode.

5) determine the access point of distributed power source, wherein, the determining step of the access point of distributed power source is as follows,

If F _dER=0, choose V _dERimain transformer in electric pressure corresponding to flag bit, carries out a weight computing according to formula (d), then sorts, get D _ij" i " kV electric pressure side of the main transformer corresponding to minimum in non-vanishing numerical value is as the access point of this distributed power source;

$D_{\mathrm{ij}}=\mathrm{if}(m_{\mathrm{ij}}<m_{\max \mathrm{ij}})(\frac{C_{\mathrm{DER}}+\underset{k=1}{\overset{\mathrm{nij}}{\mathrm{\&Sigma;}}}{C}_{\mathrm{DERk}}}{C_{\mathrm{Tij}}}+\frac{d_{\mathrm{ij}}}{d_i})---\left(d\right)$

In above formula,

M _maxijthe voltage an of-present situation jth main transformer is the quantity of " i " kV outgoing line interval;

M _ijthe voltage an of-present situation jth main transformer is the quantity of outlet in " i " kV outgoing line interval;

N _ijthe voltage an of-present situation jth main transformer is the quantity that " i " kV side joint enters distributed power source;

C _dERkthe voltage an of-present situation jth main transformer is the installed capacity of " i " kV side kth distributed power source;

D _ij-this distributed power source is " i " kV side grid power source linear distance to the voltage of a jth main transformer;

D _i-place power supply enterprise is the upper limit of the reasonable power supply distance of regulation of " i " kV electric pressure about voltage;

If F _dER=1, then this distributed power source accesses the circuit that voltage is " i " kV nearby;

Although if V _dERi=1, but " i " kV electrical network is discontented is enough to the determined condition of step, then need to forward to a upper electric pressure net of " i " kV electrical network and again carry out according to above step and the choosing of site and access way, until determine suitable and site and access way.

The above is only the preferred embodiment of the present invention, it should be pointed out that for those skilled in the art, under the premise without departing from the principles of the invention, can also make some improvement, and these improvement also should be considered as protection scope of the present invention.

Claims (6)

1. distributed power source site and an access way choosing method, is characterized in that, comprise the following steps:

1) the generating feature needing grid-connected distributed power source is determined;

2) understand the grid condition of distributed power source region, add up separate unit main transformer capacity and the load of each electric pressure public transformer substation, calculate each electric pressure main transformer capacity weighted average;

3) its grid-connected electric pressure is tentatively chosen according to the generate output of distributed power source;

4) access way of distributed power source is determined;

5) access point of distributed power source is determined.

2. distributed power source according to claim 1 site and access way choosing method, is characterized in that: the distributed power source in step 1) comprises synchronous machine, asynchronous machine and inverter type distributed power source.

3. distributed power source according to claim 1 site and access way choosing method, is characterized in that: step 2) in calculate the computing formula of each electric pressure main transformer capacity weighted average as follows,

$\stackrel{\&OverBar;}{T_i}=\frac{\underset{j=1}{\overset{\mathrm{ni}}{\mathrm{\&Sigma;}}}{T}_{\mathrm{ij}}\&times;\mathrm{if}((L_{\mathrm{ij}}-L)>0)}{\underset{j=1}{\overset{\mathrm{ni}}{\mathrm{\&Sigma;}}}\mathrm{if}((L_{\mathrm{ij}}-L)>0)}---\left(a\right)$

Wherein,

-distributed power source location can be accessed by the weighted average of the main transformer capacity that voltage is " i " kV;

I-electric pressure;

Ni-distributed power source location has the main transformer quantity that voltage is " i " kV;

T _ij-distributed power source location has the capacity of the jth main transformer that voltage is " i " kV electric pressure;

L _ij-distributed power source location have voltage for " i " kV electric pressure a jth main transformer load factor;

L-constant, is the threshold value of main transformer load factor, can chooses according to grid condition;

F ((L _ij-L) >0)-judging weight, it is as (L _ij-L) >0 duration is 1, otherwise value is 0.

4. distributed power source according to claim 1 site and access way choosing method, is characterized in that: the formula choosing its grid-connected electric pressure in step 3) is as follows,

$V_{\mathrm{DERi}}=\mathrm{if}(C_{\mathrm{DER}}<\frac{\stackrel{\&OverBar;}{T_i}}{N_T})---\left(b\right)$

Wherein,

In above formula,

-distributed power source location voltage is the weighted average of the main transformer capacity of " i " kV;

I-electric pressure;

N _t-one be greater than 1 constant;

C _dERthe installed capacity of-this distributed power source;

-one numerical value, when duration is 1, otherwise is 0;

V _dERi-distributed power source access electric pressure tentatively choose flag bit, when its value is 1, expression can be incorporated to voltage for the electrical network of " i " kV, generally gets two electric pressures.

5. distributed power source according to claim 1 site and access way choosing method, is characterized in that: in step 4), the determination formula of the access way of distributed power source is,

$F_{\mathrm{DER}}=\mathrm{if}(C_{\mathrm{DER}}<\frac{C_L}{N_l})---\left(c\right)$

Wherein,

C _lthe transmission capacity of-grid-connected circuit;

N _l-one be greater than 1 constant;

F _dERthe access way of-distributed power source, its value is that 1 expression can adopt non-access via telephone line, and its value is that 0 expression adopts access via telephone line mode.

6. distributed power source according to claim 1 site and access way choosing method, is characterized in that: in step 5), the determining step of the access point of distributed power source is as follows,

If F _dER=0, choose V _dERimain transformer in electric pressure corresponding to flag bit, carries out a weight computing according to formula (d), then sorts, get D _ij" i " kV electric pressure side of the main transformer corresponding to minimum in non-vanishing numerical value is as the access point of this distributed power source;

$D_{\mathrm{ij}}=\mathrm{if}(m_{\mathrm{ij}}<m_{\max \mathrm{ij}})(\frac{C_{\mathrm{DER}}+\underset{k=1}{\overset{\mathrm{nij}}{\mathrm{\&Sigma;}}}{C}_{\mathrm{DERk}}}{C_{\mathrm{Tij}}}+\frac{d_{\mathrm{ij}}}{d_i})---\left(d\right)$

Wherein,

M _maxijthe voltage an of-present situation jth main transformer is the quantity of " i " kV outgoing line interval;

M _ijthe voltage an of-present situation jth main transformer is the quantity of outlet in " i " kV outgoing line interval;

N _ijthe voltage an of-present situation jth main transformer is the quantity that " i " kV side joint enters distributed power source;

C _dERkthe voltage an of-present situation jth main transformer is the installed capacity of " i " kV side kth distributed power source;

D _ij-this distributed power source is " i " kV side grid power source linear distance to the voltage of a jth main transformer;

D _i-place power supply enterprise is the upper limit of the reasonable power supply distance of regulation of " i " kV electric pressure about voltage;

If F _dER=1, then this distributed power source accesses the circuit that voltage is " i " kV nearby;

Although if V _dERi=1, but " i " kV electrical network is discontented is enough to determined condition, then need the upper electric pressure net forwarding " i " kV electrical network to carry out and the choosing of site and access way, until determine suitable and site and access way.