CN105790281A - Reactive compensation capacity configuration method for wind power plant of wind power base - Google Patents

Abstract

The invention relates to a reactive compensation capacity configuration method for a wind power plant of a wind power base. The reactive compensation capacity configuration method comprises the following steps of S1, calculating a minimum dynamic reactive power current value required to be injected to a power system by the wind power plant; S2, calculating a dynamic reactive power current value injected to the power system from a power generator set in the wind power plant; and S3, determining a capacity demand of a reactive compensation device of the wind power base. The method provided by the invention is easy to implement, the requirement of engineering calculation is met, and a reference basis is provided for planning and construction of reactive power of the wind power plant in a large-scale wind power base.

Description

Wind power base Reactive Compensation in Wind Farm capacity collocation method

Technical field

The invention belongs to technical field of wind power generation, be specifically related to a kind of wind power base Reactive Compensation in Wind Farm capacity collocation method.

Background technology

Along with China's wind capacity integrated into grid is continuously increased, when large-scale wind power accesses weak end electrical network, the problem of reactive power/voltage control difficulty becomes increasingly conspicuous.Since 2011, China " three Norths " area there occurs repeatedly large-scale wind power off-grid accident, causes voltage fluctuation to regional power grid, frequency is greatly reduced, lose the serious consequences such as large area load.Accident analysis shows, wind power system voltage pulsation or unstability that wind energy turbine set dynamic reactive regulating power deficiency causes are one of major reasons causing the extensive chain off-grid of blower fan.

Configuring dynamic reactive compensation device in wind energy turbine set is improve wind-powered electricity generation to collect the important technical of area reactive power/voltage control ability.On November 30th, 2011, standard GB/T/T19963-2011 " wind energy turbine set accesses power system technology regulation " issues, and formally implement on June 1st, 2012, wherein to total installation of generating capacity at million kilowatt scale and above wind farm group, require when power system generation three phase short circuit fault, each wind energy turbine set should have dynamic reactive enabling capabilities in low voltage crossing process, and proposes clear and definite index request.But in the actual grid-connected planning of wind energy turbine set, design for reactive power compensator, the general reactive requirement only considering wind energy turbine set steady-state operation, do not consider the requirement of wind energy turbine set dynamic reactive enabling capabilities, therefore, it is necessary the specific requirement according to GB/T19963-2011 " wind energy turbine set accesses power system technology and specifies ", it is proposed to the collocation method of Reactive Compensation in Wind Farm installed capacity.

Summary of the invention

In view of this, it is an object of the invention to provide a kind of wind power base Reactive Compensation in Wind Farm capacity collocation method, the method is easily achieved, and meets the requirement of engineering calculation, and the planning construction idle for wind energy turbine set in large-scale wind electricity base provides reference frame.

The present invention adopts below scheme to realize: a kind of wind power base Reactive Compensation in Wind Farm capacity collocation method, comprises the following steps:

Step S1: according to GB/T19963-2011 " wind energy turbine set the accesses power system technology directive/guide " requirement that wind energy turbine set dynamic reactive is supported, calculate the minimum dynamic reactive current value that wind energy turbine set needs to inject to power system；

Step S2: calculate the dynamic reactive current value that in wind energy turbine set, Wind turbines injects to power system；

Step S3: determine the capacity requirement of Reactive Compensation in Wind Farm device.

Further, described step S1 is particularly as follows: in low voltage crossing process, wind energy turbine set is injected the reactive current value of power system and is at least:

I_T=1.5 × (0.9-U_T)I_N, (0.2≤U_T≤0.9)(1)

In formula, U_TResidual voltage perunit value for point voltage wind farm grid-connected in failure process；I_NFor wind energy turbine set rated current；

According to formula (1) calculate respectively wind farm grid-connected point voltage drop to 0.2p.u., 0.35p.u., 0.5p.u., 0.75p.u. and 0.9p.u. time, wind energy turbine set need to power system inject minimum dynamic reactive current value.

Further, described step S2 comprises the following steps:

Step S21: according to Wind turbines dynamic reactive current control method and low voltage ride-through capability examining report, obtain Wind turbines when exerting oneself greatly, when set end voltage drops to 0.2p.u., 0.35p.u., 0.5p.u., 0.75p.u. and 0.9p.u. respectively, the dynamic reactive current value of Wind turbines injected system；

Step S22: Wind turbines dynamic reactive electric current is converted a wind farm grid-connected side, and calculate wind farm grid-connected point respectively when dropping to 0.2p.u., 0.35p.u., 0.5p.u., 0.75p.u. and 0.9p.u., the summation after the dynamic reactive electric current conversion that all Wind turbines of wind energy turbine set provide during fault.

It is also preferred that the left ignore the impact that wind energy turbine set is electrically distributed in the calculating of described step S2, namely wind farm grid-connected point voltage falls that to fall specification with Wind turbines set end voltage identical.

Further, in described step S22, calculate Wind turbines dynamic reactive electric current according to below equation (2) and convert the reactive current value of a wind farm grid-connected side:

$I_{qi\_WT}^{PCC}=\frac{a\·I_{qi\_WT}}{K_{GSU}\·K_B}---\left(2\right)$

In formula, I_{qi_WT}It it is the i-th typhoon group of motors dynamic reactive current value；K_GSUNo-load voltage ratio for wind energy turbine set main transformer；K_BNo-load voltage ratio for wind turbine transformer；A is reactive loss coefficient, and the span of a is 0.7 to 0.8.

The summation after the dynamic reactive electric current conversion that all Wind turbines of wind energy turbine set provide during fault is calculated according to below equation (3):

$I_{qi\_WT}^{PCC}=\underset{i=1}{\overset{m}{\Σ}}{I}_{qi\_WT}^{PCC}---\left(3\right)$

In formula,It it is the dynamic reactive current value after the i-th typhoon group of motors conversion；For the summation after all Wind turbines dynamic reactive electric currents conversion in wind energy turbine set；M is the number of units of Wind turbines.

Further, described step S3 comprises the following steps:

Step S31: calculate wind farm grid-connected point voltage when dropping to 0.2p.u., 0.35p.u., 0.5p.u., 0.75p.u. and 0.9p.u. respectively, according toCalculate the reactive current value that Reactive Compensation in Wind Farm device sends；

Step S32: take wind farm grid-connected point voltage when dropping to 0.2p.u., 0.35p.u., 0.5p.u., 0.75p.u. and 0.9p.u. respectively, the maximum of the reactive current value sent by reactive power compensator as its rated current, then can calculate the capacity requirement of Reactive Compensation in Wind Farm device according to below equation (4):

Q_pwh=U_{N_SVG}·I_{cmax_SVG}(4)

In formula, Q_SVGCapacity requirement for Reactive Compensation in Wind Farm device；U_{N_SVG}Rated voltage for Reactive Compensation in Wind Farm device；I_{cmax_SVG}The maximum of the reactive current value sent is needed for reactive power compensator.

Compared with prior art, during the present invention has taken into full account electric network fault, the dynamic reactive current needs of wind energy turbine set in large-scale wind electricity base, the translation method of the dynamic reactive electric current that the Wind turbines proposed injects to power system, calculate simple, the empirical value that reactive loss coefficient a is multiple wind energy turbine set simulation example provided in formula (2), error is less；And the method is easily achieved, meeting the requirement of engineering calculation, the planning construction idle for wind energy turbine set in large-scale wind electricity base provides reference frame.

Accompanying drawing explanation

Fig. 1 is the method flow schematic diagram of the present invention.

The method flow schematic diagram of the step S2 of Fig. 2 position present invention.

Detailed description of the invention

Below in conjunction with drawings and Examples, the present invention will be further described.

The present embodiment provides a kind of wind power base Reactive Compensation in Wind Farm capacity collocation method, comprises the following steps:

Step S1: according to GB/T19963-2011 " wind energy turbine set the accesses power system technology directive/guide " requirement that wind energy turbine set dynamic reactive is supported, calculate wind energy turbine set and fall, in also site exemplary voltages, the reactive current value needing to inject to system under specification；

Step S2: calculate wind farm grid-connected point under exemplary voltages falls specification, the dynamic reactive current value injected to system between Wind turbines age at failure in wind energy turbine set；

Step S3: determine that wind energy turbine set needs the dynamic reactive compensation device capacity of configuration.

In the present embodiment, described step S1 is particularly as follows: in low voltage crossing process, wind energy turbine set is injected the reactive current value of power system and is at least:

I_T=1.5 × (0.9-U_T)I_N, (0.2≤U_T≤0.9)(1)

In formula, U_TResidual voltage perunit value for point voltage wind farm grid-connected in failure process；I_NFor wind energy turbine set rated current；

According to formula (1) calculate respectively wind farm grid-connected point voltage drop to 0.2p.u., 0.35p.u., 0.5p.u., 0.75p.u. and 0.9p.u. time, wind energy turbine set need to power system inject minimum dynamic reactive current value.

In the present embodiment, described step S2 comprises the following steps:

Step S21: according to Wind turbines dynamic reactive current control method and low voltage ride-through capability examining report, obtain Wind turbines when exerting oneself greatly, when set end voltage drops to 0.2p.u., 0.35p.u., 0.5p.u., 0.75p.u. and 0.9p.u. respectively, the dynamic reactive current value of Wind turbines injected system；

Step S22: Wind turbines dynamic reactive electric current is converted a wind farm grid-connected side, and calculate wind farm grid-connected point respectively when dropping to 0.2p.u., 0.35p.u., 0.5p.u., 0.75p.u. and 0.9p.u., the summation after the dynamic reactive electric current conversion that all Wind turbines of wind energy turbine set provide during fault.

It is also preferred that the left ignore the impact that wind energy turbine set is electrically distributed in the calculating of described step S2, namely wind farm grid-connected point voltage falls that to fall specification with Wind turbines set end voltage identical.

In the present embodiment, in described step S22, calculate Wind turbines dynamic reactive electric current according to below equation (2) and convert the reactive current value of a wind farm grid-connected side:

$I_{qi\_WT}^{PCC}=\frac{a\·I_{qi\_WT}}{K_{GSU}\·K_B}---\left(2\right)$

In formula, I_{qi_WT}It it is the i-th typhoon group of motors dynamic reactive current value；K_GSUNo-load voltage ratio for wind energy turbine set main transformer；K_BNo-load voltage ratio for wind turbine transformer；A is reactive loss coefficient, and the span of a is 0.7 to 0.8.

The summation after the dynamic reactive electric current conversion that all Wind turbines of wind energy turbine set provide during fault is calculated according to below equation (3):

$I_{qi\_WT}^{PCC}=\underset{i=1}{\overset{m}{\Σ}}{I}_{qi\_WT}^{PCC}---\left(3\right)$

In formula,It it is the dynamic reactive current value after the i-th typhoon group of motors conversion；For the summation after all Wind turbines dynamic reactive electric currents conversion in wind energy turbine set；M is the number of units of Wind turbines.

In the present embodiment, described step S3 comprises the following steps:

Step S31: calculate wind farm grid-connected point voltage when dropping to 0.2p.u., 0.35p.u., 0.5p.u., 0.75p.u. and 0.9p.u. respectively, according toCalculate the reactive current value that Reactive Compensation in Wind Farm device sends；

Step S32: take wind farm grid-connected point voltage when dropping to 0.2p.u., 0.35p.u., 0.5p.u., 0.75p.u. and 0.9p.u. respectively, the maximum of the reactive current value sent by reactive power compensator as its rated current, then can calculate the capacity requirement of Reactive Compensation in Wind Farm device according to below equation (4):

Q_SVG=U_{N_SVG}·I_{cmax_SVG}(4)

In formula, Q_SVGCapacity requirement for Reactive Compensation in Wind Farm device；U_{N_SVG}Rated voltage for Reactive Compensation in Wind Farm device；I_{cmax_SVG}The maximum of the reactive current value sent is needed for reactive power compensator.

The foregoing is only presently preferred embodiments of the present invention, all equalizations done according to the present patent application the scope of the claims change and modify, and all should belong to the covering scope of invention.

Claims (6)

1. a wind power base Reactive Compensation in Wind Farm capacity collocation method, it is characterised in that: comprise the following steps:

Step S1: calculate the minimum dynamic reactive current value that wind energy turbine set needs to inject to power system；

Step S2: calculate the dynamic reactive current value that in wind energy turbine set, Wind turbines injects to power system；

Step S3: determine the capacity requirement of Reactive Compensation in Wind Farm device.

2. a kind of wind power base Reactive Compensation in Wind Farm capacity collocation method according to claim 1, it is characterised in that: described step S1 is particularly as follows: in low voltage crossing process, wind energy turbine set is injected the reactive current value of power system and is at least:

I_T=1.5 × (0.9-U_T)I_N, (0.2≤U_T≤0.9)(1)

In formula, U_TResidual voltage perunit value for point voltage wind farm grid-connected in failure process；I_NFor wind energy turbine set rated current；

According to formula (1) calculate respectively wind farm grid-connected point voltage drop to 0.2p.u., 0.35p.u., 0.5p.u., 0.75p.u. and 0.9p.u. time, wind energy turbine set need to power system inject minimum dynamic reactive current value.

3. a kind of wind power base Reactive Compensation in Wind Farm capacity collocation method according to claim 1, it is characterised in that: described step S2 comprises the following steps:

Step S21: according to Wind turbines dynamic reactive current control method and low voltage ride-through capability examining report, obtain Wind turbines when exerting oneself greatly, when set end voltage drops to 0.2p.u., 0.35p.u., 0.5p.u., 0.75p.u. and 0.9p.u. respectively, the dynamic reactive current value of Wind turbines injected system；

Step S22: Wind turbines dynamic reactive electric current is converted a wind farm grid-connected side, and calculate wind farm grid-connected point respectively when dropping to 0.2p.u., 0.35p.u., 0.5p.u., 0.75p.u. and 0.9p.u., the summation after the dynamic reactive electric current conversion that all Wind turbines of wind energy turbine set provide during fault.

4. a kind of wind power base Reactive Compensation in Wind Farm capacity collocation method according to claim 3, it is characterized in that: ignore the impact that wind energy turbine set is electrically distributed in the calculating of described step S2, namely wind farm grid-connected point voltage falls that to fall specification with Wind turbines set end voltage identical.

5. a kind of wind power base Reactive Compensation in Wind Farm capacity collocation method according to claim 3, it is characterized in that: in described step S22, calculate Wind turbines dynamic reactive electric current according to below equation (2) and convert the reactive current value of a wind farm grid-connected side:

In formula, I_{qi_WT}It it is the i-th typhoon group of motors dynamic reactive current value；K_GSUNo-load voltage ratio for wind energy turbine set main transformer；K_BNo-load voltage ratio for wind turbine transformer；A is reactive loss coefficient, and the span of a is 0.7 to 0.8.

The summation after the dynamic reactive electric current conversion that all Wind turbines of wind energy turbine set provide during fault is calculated according to below equation (3):

In formula,It it is the dynamic reactive current value after the i-th typhoon group of motors conversion；For the summation after all Wind turbines dynamic reactive electric currents conversion in wind energy turbine set；M is the number of units of Wind turbines.

6. a kind of wind power base Reactive Compensation in Wind Farm capacity collocation method according to claim 1, it is characterised in that: described step S3 comprises the following steps:

Step S31: calculate wind farm grid-connected point voltage when dropping to 0.2p.u., 0.35p.u., 0.5p.u., 0.75p.u. and 0.9p.u. respectively, according toCalculate the reactive current value that Reactive Compensation in Wind Farm device sends；

Step S32: take wind farm grid-connected point voltage when dropping to 0.2p.u., 0.35p.u., 0.5p.u., 0.75p.u. and 0.9p.u. respectively, the maximum of the reactive current value sent by reactive power compensator as its rated current, then can calculate the capacity requirement of Reactive Compensation in Wind Farm device according to below equation (4):

Q_SVG=U_{N_SVG}·I_{cmax_SVG}(4)

In formula, Q_SVGCapacity requirement for Reactive Compensation in Wind Farm device；U_{N_SVG}Rated voltage for Reactive Compensation in Wind Farm device；I_{cmax_SVG}The maximum of the reactive current value sent is needed for reactive power compensator.