CN104967120A - Constant power interface-based hybrid dynamic simulation method - Google Patents

Abstract

The invention provides a constant power interface-based hybrid dynamic simulation method. The method includes the following steps that: a power system is divided into a plurality of subsystems; a time sequence of equal time intervals is obtained; the initial power flow of the subsystems is obtained; and the injection current of a boundary bus and the voltage simulation curve of the boundary bus are determined. According to the method of the invention, a constant power interface can guarantee the consistency of the switching power of a research power grid and an external power grid and a measured value in a whole simulation period, and therefore, a foundation can be laid for the practical application of the hybrid dynamic simulation method.

Description

A kind of hybrid dynamic simulation method based on invariable power interface

Technical field

The invention belongs to technical field of power systems, be specifically related to a kind of hybrid dynamic simulation method based on invariable power interface.

Background technology

Along with electrical network popularization and grid structure strengthen, the impact of any one disturbance is diffused into vast region, and each change is the result that a large amount of factor interweaves, and makes the reason of checking validity of simulation and location simulation error very difficult.Traditional dynamic simulation is mainly at the load generator operation mode preset and predefine failure mode, and the accuracy of the model and algorithl that places one's entire reliance upon in simulation process, does not contact with real system.The inaccuracy of model or parameter may cause the deviation between simulation result and real system dynamic behaviour.Simultaneously, there is WAMS (the Wide Area MeasurementSystem of phase mass brake, WAMS) in electrical network, widely apply the dynamic behaviour that can catch electrical network accurately, but the every nook and cranny of system can not be arranged on, and can not the behavior of prognoses system as emulation.Therefore, emulation and WAMS measurement have respective pluses and minuses, both advantages are joined together by electric power system hybrid dynamic simulation, for traditional dynamic simulation provides the interface of a measurement data, for systematic failures reproduction, simulating, verifying etc. need the work of accurate contrast simulation result and measurement result to provide a platform, be that the fault message that profound excavation measurement data itself comprises provides method basis.

Hybrid dynamic simulation uses phasor measurement unit (Phasor Measurement Unit, PMU) external signal collected is injected in simulation subsystem, thus electrical network external system is carried out equivalence, and simulation result and WAMS are measured compare, with location simulation deviating cause, verification component parameters etc.Hybrid dynamic simulation needs the effect that should embody external electrical network, for meeting interface requirement, can not inject larger side-play amount to research electrical network again, making simulation process depart from the normal operation characteristic of research electrical network.The implementation method of conventional hybrid dynamic simulation mainly contains phase shifting transformer method, fast reaction dynamo method, impedance method, V-θ nodal method etc.These methods, in fact all by the level angle of equivalent point and PMU data consistent, when simulation process electric current departs from actual value comparatively greatly, are equivalent to be filled with larger deviation power, force research electrical network internal power source state to change.Add the difficulty of analysis element and device behavioral trait, the practical formation of hybrid dynamic simulation method is hindered.

Summary of the invention

In order to overcome above-mentioned the deficiencies in the prior art, the invention provides a kind of hybrid dynamic simulation method based on invariable power interface, comprehensive flexible constraint is formed to border busbar voltage, electric current, research electrical network is affected by interface little, fully can represent the characteristic of research electrical network self.The method is that the practical of hybrid dynamic simulation method is laid a good foundation.

In order to realize foregoing invention object, the present invention takes following technical scheme:

The invention provides a kind of hybrid dynamic simulation method based on invariable power interface, said method comprising the steps of:

Step 1: electric power system is divided into multiple subsystem;

Step 2: the time ordinal series obtaining constant duration;

Step 3: increase invariable power interface at bus place, border, and obtain the initial trend of subsystem;

Step 4: Injection Current and the border busbar voltage simulation curve of determining border bus.

In described step 1, layouting according to phasor measurement unit, is divided into multiple subsystem by electric power system, is connected between each subsystem by border bus, and described border bus is the bus installing phasor measurement unit.

Described step 2 specifically comprises the following steps:

Step 2-1: by collection border bus information and the subsystem injection information of phasor measurement unit constant duration, described border bus information comprises voltage magnitude and the voltage phase angle of border bus, and described subsystem injects information and comprises subsystem injection active power and reactive power;

Step 2-2: the border bus information of collection and subsystem are injected information and carries out preliminary treatment, if time series is { t ₁, t ₂..., t _n, then the time ordinal series of corresponding constant duration is { y ₁, y ₂..., y _n, data amount check in ordinal series when N represents, is divided into following two kinds of situations:

1) if time ordinal series in data be shortage of data point, then utilize difference method to data missing point y _icarry out polishing, have:

$y_i=y_{i-1}+\frac{y_{i+1}-y_{i-1}}{t_{i+1}-t_{i-1}}(t_i-t_{i-1})---\left(1\right)$

In formula (1), y _i-1the i-th-1 data missing point in ordinal series during expression, y _i+1the i-th+1 data missing point in ordinal series during expression, t _i-1represent shortage of data point y _i-1the corresponding time, t _i+1represent shortage of data point y _i+1the corresponding time, ti represents shortage of data point y _ithe corresponding time;

2) for time ordinal series in arbitrary data, if it is greater than 3 times of 2 statistical average before and after it, then these data are data error point, are designated as y _j, utilize the method for mean value to remove data error point y _jin burr and sudden change, obtain smoothed curve, y _jbe expressed as:

$y_j=y_{j-1}+\frac{y_{j+1}-y_{j-1}}{t_{j+1}-t_{j-1}}(t_j-t_{j-1})---\left(2\right)$

In formula (2), y _j-1jth-1 data error point in ordinal series during expression, y _j+1jth+1 data error point in ordinal series during expression, t _j-1represent the time that data error point j-1 is corresponding, t _j+1represent the time that data error point j+1 is corresponding, t _jrepresent data error point y _jthe corresponding time.

In described step 3, first increase invariable power interface at bus place, border, it is consistent that initial injection active power and the subsystem gathered by phasor measurement unit of invariable power interface inject active power, and it is consistent that initial injection reactive power and the subsystem gathered by phasor measurement unit of invariable power interface inject reactive power; In utilizing, some Optimal Power Flow algorithm obtains the initial trend of subsystem, makes initial trend and phasor measurement unit record ripple initial point voltage close, first data point in ordinal series when phasor measurement unit record ripple initial point is.

The initial trend of subsystem is optimized by target function, has:

$\begin{array}{cc}\underset{u}{min}& f(u,x)=\underset{l\≤M}{\Σ}{(v_l-{\hat{v}}_l)}^2---\end{array}\left(3\right)$

In formula (3), u represents control variables, and what comprise generator meritoriously to exert oneself and the idle of generator is exerted oneself; X represents state variable to be tried to achieve, and comprises voltage magnitude and voltage phase angle; v _lrepresent the measuring voltage of l border bus, represent the initial voltage of l border bus, M represents the number of system border bus;

The constraints that target function is corresponding comprises equality constraint and inequality constraints condition, and equality constraint and inequality constraints condition are expressed as:

g(u,x)＝0 (4)

h(u,x)≤0 (5)

In formula (4) and (5), g (u, x) represents equality constraint, and h (u, x) represents inequality constraints.

Described step 4 specifically comprises the following steps:

Step 4-1: emulation initial time T=0 is set, and according to time ordinal series the time interval simulation step length is set;

Step 4-2: utilize trapezoidal integration algorithm to emulate, obtains bus place, border Injection Current be expressed as:

$\stackrel{\·}{I}=I_x+{\mathrm{jI}}_y---\left(6\right)$

In formula (6), I _xrepresent bus place, border Injection Current real part, I _yrepresent bus place, border Injection Current imaginary part; And have:

$I_x=\frac{P\·V_x+Q\·V_y}{S\·({V_x}^2+{V_y}^2)}---\left(7\right)$

$I_y=\frac{P\·V_y-Q\·V_x}{S\·({V_x}^2+{V_y}^2)}---\left(8\right)$

In formula (7) and (8), P represents that the subsystem gathered by phasor measurement units injects active power, and Q represents that the subsystem gathered by phasor measurement units injects reactive power, and S represents power reference value; Border busbar voltage be expressed as:

$\stackrel{\·}{V}=V_x+{\mathrm{jV}}_y---\left(9\right)$

In formula (9), V _xrepresent border busbar voltage real part, V _yrepresent border busbar voltage imaginary part;

Step 4-3: obtain border busbar voltage simulation curve by hybrid dynamic simulation.

Compared with prior art, beneficial effect of the present invention is:

Hybrid dynamic simulation method based on invariable power interface provided by the invention, by electric power system is divided into multiple subsystem, and obtains the time ordinal series of constant duration; After obtaining the initial trend of subsystem, obtain Injection Current and the border busbar voltage simulation curve of border bus.During invariable power interface ensures whole emulation, research electrical network is consistent with measured value with the exchange power of external electrical network, for the practical of hybrid dynamic simulation method is laid a good foundation.

Accompanying drawing explanation

Fig. 1 is the hybrid dynamic simulation method flow diagram based on invariable power interface in the embodiment of the present invention;

Fig. 2 is subsystem and border bus graph of a relation in the embodiment of the present invention.

Embodiment

Below in conjunction with accompanying drawing, the present invention is described in further detail.

As Fig. 1, the invention provides a kind of hybrid dynamic simulation method based on invariable power interface, said method comprising the steps of:

Step 1: electric power system is divided into multiple subsystem;

Step 2: the time ordinal series obtaining constant duration;

Step 3: increase invariable power interface at bus place, border, and obtain the initial trend of subsystem;

Step 4: Injection Current and the border busbar voltage simulation curve of determining border bus.

In described step 1, layouting according to phasor measurement unit, is divided into multiple subsystem by electric power system, is connected between each subsystem by border bus, and described border bus is the bus installing phasor measurement unit.

Described step 2 specifically comprises the following steps:

Step 2-1: by collection border bus information and the subsystem injection information of phasor measurement unit constant duration, described border bus information comprises voltage magnitude and the voltage phase angle of border bus, and described subsystem injects information and comprises subsystem injection active power and reactive power;

Step 2-2: the border bus information of collection and subsystem are injected information and carries out preliminary treatment, if time series is { t ₁, t ₂..., t _n, then the time ordinal series of corresponding constant duration is { y ₁, y ₂..., y _n, data amount check in ordinal series when N represents, is divided into following two kinds of situations:

1) if time ordinal series in data be shortage of data point, then utilize difference method to data missing point y _icarry out polishing, have:

$y_i=y_{i-1}+\frac{y_{i+1}-y_{i-1}}{t_{i+1}-t_{i-1}}(t_i-t_{i-1})---\left(1\right)$

In formula (1), y _i-1the i-th-1 data missing point in ordinal series during expression, y _i+1the i-th+1 data missing point in ordinal series during expression, t _i-1represent shortage of data point y _i-1the corresponding time, t _i+1represent shortage of data point y _i+1the corresponding time, ti represents shortage of data point y _ithe corresponding time;

2) for time ordinal series in arbitrary data, if it is greater than 3 times of 2 statistical average before and after it, then these data are data error point, are designated as y _j, utilize the method for mean value to remove data error point y _jin burr and sudden change, obtain smoothed curve, y _jbe expressed as:

$y_j=y_{j-1}+\frac{y_{j+1}-y_{j-1}}{t_{j+1}-t_{j-1}}(t_j-t_{j-1})---\left(2\right)$

In formula (2), y _j-1jth-1 data error point in ordinal series during expression, y _j+1jth+1 data error point in ordinal series during expression, t _j-1represent the time that data error point j-1 is corresponding, t _j+1represent the time that data error point j+1 is corresponding, t _jrepresent data error point y _jthe corresponding time.

In described step 3, first increase invariable power interface at bus place, border, it is consistent that initial injection active power and the subsystem gathered by phasor measurement unit of invariable power interface inject active power, and it is consistent that initial injection reactive power and the subsystem gathered by phasor measurement unit of invariable power interface inject reactive power; In utilizing, some Optimal Power Flow algorithm obtains the initial trend of subsystem, makes initial trend and phasor measurement unit record ripple initial point voltage close, first data point in ordinal series when phasor measurement unit record ripple initial point is.

The initial trend of subsystem is optimized by target function, has:

$\begin{array}{cc}\underset{u}{min}& f(u,x)=\underset{l\≤M}{\Σ}{(v_l-{\hat{v}}_l)}^2---\end{array}\left(3\right)$

In formula (3), u represents control variables, and what comprise generator meritoriously to exert oneself and the idle of generator is exerted oneself; X represents state variable to be tried to achieve, and comprises voltage magnitude and voltage phase angle; v _lrepresent the measuring voltage of l border bus, represent the initial voltage of l border bus, M represents the number of system border bus;

The constraints that target function is corresponding comprises equality constraint and inequality constraints condition, and equality constraint and inequality constraints condition are expressed as:

g(u,x)＝0 (4)

h(u,x)≤0 (5)

In formula (4) and (5), g (u, x) represents equality constraint, and h (u, x) represents inequality constraints.

Described step 4 specifically comprises the following steps:

Step 4-1: emulation initial time T=0 is set, and according to time ordinal series the time interval simulation step length is set;

Step 4-2: utilize trapezoidal integration algorithm to emulate, obtains bus place, border Injection Current be expressed as:

$\stackrel{\·}{I}=I_x+{\mathrm{jI}}_y---\left(6\right)$

In formula (6), I _xrepresent bus place, border Injection Current real part, I _yrepresent bus place, border Injection Current imaginary part; And have:

$I_x=\frac{P\·V_x+Q\·V_y}{S\·({V_x}^2+{V_y}^2)}---\left(7\right)$

$I_y=\frac{P\·V_y-Q\·V_x}{S\·({V_x}^2+{V_y}^2)}---\left(8\right)$

In formula (7) and (8), P represents that the subsystem gathered by phasor measurement units injects active power, and Q represents that the subsystem gathered by phasor measurement units injects reactive power, and S represents power reference value; Border busbar voltage be expressed as:

$\stackrel{\·}{V}=V_x+{\mathrm{jV}}_y---\left(9\right)$

In formula (9), V _xrepresent border busbar voltage real part, V _yrepresent border busbar voltage imaginary part;

Step 4-3: obtain border busbar voltage simulation curve by hybrid dynamic simulation.

Finally should be noted that: above embodiment is only in order to illustrate that technical scheme of the present invention is not intended to limit, although with reference to above-described embodiment to invention has been detailed description, those of ordinary skill in the field are to be understood that: still can modify to the specific embodiment of the present invention or equivalent replacement, and not departing from any amendment of spirit and scope of the invention or equivalent replacement, it all should be encompassed in the middle of right of the present invention.

Claims (6)

1., based on a hybrid dynamic simulation method for invariable power interface, it is characterized in that: said method comprising the steps of:

Step 1: electric power system is divided into multiple subsystem;

Step 2: the time ordinal series obtaining constant duration;

Step 3: increase invariable power interface at bus place, border, and obtain the initial trend of subsystem;

Step 4: Injection Current and the border busbar voltage simulation curve of determining border bus.

2. the hybrid dynamic simulation method based on invariable power interface according to claim 1, it is characterized in that: in described step 1, layouting according to phasor measurement unit, electric power system is divided into multiple subsystem, connected by border bus between each subsystem, described border bus is the bus installing phasor measurement unit.

3. the hybrid dynamic simulation method based on invariable power interface according to claim 1, is characterized in that: described step 2 specifically comprises the following steps:

Step 2-1: by collection border bus information and the subsystem injection information of phasor measurement unit constant duration, described border bus information comprises voltage magnitude and the voltage phase angle of border bus, and described subsystem injects information and comprises subsystem injection active power and reactive power;

Step 2-2: the border bus information of collection and subsystem are injected information and carries out preliminary treatment, if time series is { t ₁, t ₂..., t _n, then the time ordinal series of corresponding constant duration is { y ₁, y ₂..., y _n, data amount check in ordinal series when N represents, is divided into following two kinds of situations:

1) if time ordinal series in data be shortage of data point, then utilize difference method to data missing point y _icarry out polishing, have:

$y_i=y_{i-1}+\frac{y_{i+1}-y_{i-1}}{t_{i+1}-t_{i-1}}(t_i-t_{i-1})---\left(1\right)$

In formula (1), y _i-1the i-th-1 data missing point in ordinal series during expression, y _i+1the i-th+1 data missing point in ordinal series during expression, t _i-1represent shortage of data point y _i-1the corresponding time, t _i+1represent shortage of data point y _i+1the corresponding time, t _irepresent shortage of data point y _ithe corresponding time;

2) for time ordinal series in arbitrary data, if it is greater than 3 times of 2 statistical average before and after it, then these data are data error point, are designated as y _j, utilize the method for mean value to remove data error point y _jin burr and sudden change, obtain smoothed curve, y _jbe expressed as:

$y_j=y_{j-1}+\frac{y_{j+1}-y_{j-1}}{t_{j+1}-t_{j-1}}(t_y-t_{j-1})---\left(2\right)$

In formula (2), y _j-1jth-1 data error point in ordinal series during expression, y _j+1jth+1 data error point in ordinal series during expression, t _j-1represent the time that data error point j-1 is corresponding, t _j+1represent the time that data error point j+1 is corresponding, t _jrepresent data error point y _jthe corresponding time.

4. the hybrid dynamic simulation method based on invariable power interface according to claim 1, it is characterized in that: in described step 3, first increase invariable power interface at bus place, border, it is consistent that initial injection active power and the subsystem gathered by phasor measurement unit of invariable power interface inject active power, and it is consistent that initial injection reactive power and the subsystem gathered by phasor measurement unit of invariable power interface inject reactive power; In utilizing, some Optimal Power Flow algorithm obtains the initial trend of subsystem, makes initial trend and phasor measurement unit record ripple initial point voltage close, first data point in ordinal series when phasor measurement unit record ripple initial point is.

5. the hybrid dynamic simulation method based on invariable power interface according to claim 4, is characterized in that: the initial trend of subsystem is optimized by target function, has:

$\underset{u}{min}f(u,x)=\underset{l\≤M}{\Σ}{(v_l-{\hat{v}}_l)}^2---\left(3\right)$

In formula (3), u represents control variables, and what comprise generator meritoriously to exert oneself and the idle of generator is exerted oneself; X represents state variable to be tried to achieve, and comprises voltage magnitude and voltage phase angle; v _lrepresent the measuring voltage of l border bus, represent the initial voltage of l border bus, M represents the number of system border bus;

The constraints that target function is corresponding comprises equality constraint and inequality constraints condition, and equality constraint and inequality constraints condition are expressed as:

g(u,x)＝0 (4)

h(u,x)≤0 (5)

In formula (4) and (5), g (u, x) represents equality constraint, and h (u, x) represents inequality constraints.

6. the hybrid dynamic simulation method based on invariable power interface according to claim 1, is characterized in that: described step 4 specifically comprises the following steps:

Step 4-1: emulation initial time T=0 is set, and according to time ordinal series the time interval simulation step length is set;

Step 4-2: utilize trapezoidal integration algorithm to emulate, obtains bus place, border Injection Current be expressed as:

$\stackrel{\·}{I}=I_x+{\mathrm{jI}}_y---\left(6\right)$

In formula (6), I _xrepresent bus place, border Injection Current real part, I _yrepresent bus place, border Injection Current imaginary part; And have:

$I_x=\frac{P\·V_x+Q\·V_y}{S\·({V_x}^2+{V_y}^2)}---\left(7\right)$

$I_y=\frac{P\·V_y-Q\·V_x}{S\·({V_x}^2+{V_y}^2)}---\left(8\right)$

In formula (7) and (8), P represents that the subsystem gathered by phasor measurement units injects active power, and Q represents that the subsystem gathered by phasor measurement units injects reactive power, and S represents power reference value; Border busbar voltage be expressed as:

$\stackrel{\·}{V}=V_x+{\mathrm{jV}}_y---\left(9\right)$

In formula (9), V _xrepresent border busbar voltage real part, V _yrepresent border busbar voltage imaginary part;

Step 4-3: obtain border busbar voltage simulation curve by hybrid dynamic simulation.