Disclosure of Invention
The technical problem to be solved by the invention is as follows: the technical problem that the energy utilization efficiency of the existing microgrid with the distributed power supply is low is solved. The dispatching method of the micro-grid with the distributed power supply based on the intelligent gateway is capable of improving energy utilization efficiency.
In order to solve the technical problems, the technical scheme adopted by the invention is as follows: a method for scheduling a microgrid with a distributed power supply based on an intelligent gateway, wherein the distributed power supply comprises an energy storage station and a wind-solar power station, comprises the following steps: A) node w for connecting target power grid with distributed power supply
i,i∈[1,n]Upper-mounted intelligent gateway
The intelligent gateway
The system comprises a communication module connected with a dispatching center, a monitoring module for monitoring the voltage and current of a node, a phase monitoring module for monitoring the phase of the node, a frequency monitoring module for monitoring the frequency of the node and a control module connected with a distributed power supply; B) dividing a day into n periods t
j,j∈[1,n]The dispatching center is provided with a next time interval t
i+1Active power prediction value of load
And reactive power prediction
Calculating the next time period t
j+1Characteristic value
If the characteristic value
Less than a set threshold lambda
thrThen t is
j+1Wind-solar power station G in time interval
i,i∈[1,l]Only outputting active power, wherein l is the number of wind-solar power stations, and entering the step D), otherwise, entering the step C); C) scheduling center computation
And determining wind and light power station G
i,i∈[1,l]Output active power
And reactive power
And satisfy
D) Will be of period t
j+1Equally dividing the time into N small time periods, wherein the starting time t of each small time period
j+1|k,k∈[1,N]Node w
iCorresponding intelligent gateway
Read node w
iVoltage and frequency on, according to node w
iVoltage and frequency on, intelligent gateway
Wind-solar power station G
iOr energy storage station E
i,i∈[1,m]And performing power control, wherein m is the number of the energy storage stations. The access scheduling task can be completed only by acquiring the corresponding state data of the nodes through the monitoring module, the phase monitoring module and the frequency monitoring module, the installation and the expansion are convenient, and the method is suitable for the access of the distributed power supply. When the proportion of the reactive power in the distribution network is large, the distributed power supply is dispatched to output partial reactive power, although partial benefits can be reduced, the power factor of the transformer can be effectively improved, the stability of the microgrid is improved, the cost of newly adding the traditional energy source for adapting to the access of the renewable energy source is obviously reduced, and the distributed power supply dispatching method is suitable for dispatching the microgrid with the renewable energy source with high permeability.
Preferably, in step C), the time period t
j+1Internal wind and light power station G
i,i∈[1,l]Active power of
And reactive power
The distribution method comprises the following steps: C11) establishing an evaluation function
For feeder i during time period t
j+1The average active power transferred in-between,
for feeder i during time period t
j+1The average reactive power transferred in-between,
h is the number of feeders, i is the upper limit of the load of the feeder i; C12) using an optimization algorithm, an evaluation function is obtained
Minimum value wind-solar power station G
i,i∈[1,l]Reactive power of
Value, active power
For wind-solar power station G
i,i∈[1,l]Real-time force is applied. The power flow of the feeder line is optimized, and the overall transmission capacity of the feeder line is improved.
Preferably, in step C12), the wind-solar power station G is calculated
i,i∈[1,l]Operating power factor of
Time period t
j+1Internal active power
And reactive power
Is distributed to
Always holds as a constraint of the optimization algorithm, λ'
thrTo set the threshold value, λ'
thr>λ
thr. The working state of the wind and light power station is ensured to be at a better level, and excessive renewable energy waste is avoided.
Preferably, in step D), if the node w
iConnected to wind-solar power station G
iThen, the following steps are executed: if node w
iWhen the voltage is lower than the standard value, the intelligent gateway
Controlling wind-solar power station G
iIncreasing reactive power
If node w
iIf the voltage is higher than the standard value, the intelligent gateway
Controlling wind-solar power station G
iReduction of reactive power
To output of (c).
Preferably, in step D), if the node w
iConnected thereto is an energy storage station E
iThen, the following steps are executed: if node w
iWhen the voltage is lower than the standard value, the intelligent gateway
Controlling energy storage station E
iIncrease power output or decrease charging power if node w
iIf the voltage is higher than the standard value, the intelligent gateway
Controlling energy storage station E
iIncreasing the charging power or decreasing the discharging power.
Preferably, the following steps are also performed: D11) wind and light power station G
i,i∈[1,l]Real-time force of
Deviation from predicted value
Probability of deviation of
Tau is the rate of deviation and is the rate of deviation,
σ is the deviation rate τ | t
j+1The probability of occurrence; D12) time period t
j+1Internal and real-time monitoring wind-light power station G
i,i∈[1,l]Real-time force of
Deviation rate of (τ | t)
j+1If the probability of deviation is high
Then the energy storage station E is added
i,i∈[1,m]Charging power or reducing energy storage station E
i,i∈[1,m]Otherwise, the wind-light power station G is increased according to the set amplitude
i,i∈[1,l]Reactive power of output
Until real-time output
Deviation rate of (τ | t)
j+1Corresponding deviation probability
Fall back to sigma
thrThe following.
Preferably, in step D11), the deviation probability is calculated
The method comprises the following steps: D111) counting wind-light power station G in each small period
i,i∈[1,l]Mean value of real-time forces of
r∈[1,N](ii) a D112) Will be of period t
j+1The former w time periods execute the step C11), and the wind-solar power station G in each small period in each time period is obtained
i,i∈[1,l]Mean value of real-time forces of
u∈[j-w,j],r∈[1,N](ii) a D113) Statistics of
The maximum value and the minimum value of (c),
section of will
Equally dividing the data into a plurality of value intervals, and respectively counting the data falling into each interval
Of each value interval
The ratio of the number of the wind-solar power station G to w.N is used as the wind-solar power station G
i,i∈[1,l]Real-time force of
Deviation probability corresponding to falling value interval
Short-term wind-solar power station G
i,i∈[1,l]The real-time output distribution probability has certain stability, when the real-time output is at a level with lower occurrence probability, the dispatching of the distribution network does not need to be adjusted by a large margin, and only the energy storage station needs to be used for balancing real-time output fluctuation in a short time.
Preferably, in step D), the energy storage station E is controlled
i,i∈[1,m]The method for increasing the charging power or increasing the discharging power comprises the following steps: D21) computing energy storage station E
i,i∈[1,m]Total increased charging power of
Rho is a set margin coefficient, rho>1; D22) establishing an evaluation function
Where z represents the number of small cycles,
for feeder i during time period t
j+1The average load of the z-th small period of time,
h is the number of feeders, i is the upper limit of the load of the feeder i; D23) at a set time before the beginning of the z-th small period, the wind-light power station G within the (z-1) th small period to the current time
iReal-time force of
Mean value calculation of
A value of (d); D24) using an optimization algorithm, an evaluation function is obtained
Energy storage station E with the smallest value
i,i∈[1,m]The charging power is increased in real time, and the process returns to step D23) at a predetermined timing before the start of the next small cycle.
The substantial effects of the invention are as follows: the method is suitable for dispatching the microgrid of renewable energy sources with high permeability, is convenient to install and expand, and is suitable for accessing a distributed power supply; the cost of newly adding traditional energy sources for adapting to the access of renewable energy sources is reduced, the reliability and the safety of the operation of the micro-grid are improved, and the overall energy utilization efficiency of the micro-grid is improved.
Detailed Description
The following provides a more detailed description of the present invention, with reference to the accompanying drawings.
The first embodiment is as follows:
a method for scheduling a microgrid with distributed power supplies based on an intelligent gateway, wherein the distributed power supplies comprise energy storage stations and wind and light power stations, as shown in figure 1, the method comprises the following steps:
A) node w for connecting target power grid with distributed power supply
i,i∈[1,n]Upper-mounted intelligent gateway
Intelligent gateway
The system comprises a communication module 100 connected with a dispatching center, a monitoring module 200 for monitoring node voltage and current, a phase monitoring module 400 for monitoring node phase, a frequency monitoring module 500 for monitoring node frequency and a control module 300 connected with a distributed power supply.
B) Dividing a day into n periods t
j,j∈[1,n]The dispatching center is provided with a next time interval t
i+1Active power prediction value of load
And reactive power prediction
Calculating the next time period t
j+1Characteristic value
If the characteristic value
Less than a set threshold lambda
thrThen t is
j+1Wind-solar power station G in time interval
i,i∈[1,l]And only outputting active power, wherein l is the number of the wind-solar power stations, and entering the step D), and otherwise, entering the step C).
C) Scheduling center computation
And determining wind and light power station G
i,i∈[1,l]Output active power
And reactive power
And satisfy
As shown in FIG. 2, the period t
j+1Internal wind and light power station G
i,i∈[1,l]Active power of
And reactive power
The distribution method comprises the following steps: C11) establishing an evaluation function
For feeder i during time period t
j+1The average active power transferred in-between,
for feeder i during time period t
j+1The average reactive power transferred in-between,
h is the number of feeders, i is the upper limit of the load of the feeder i; C12) using an optimization algorithm, an evaluation function is obtained
Minimum value wind-solar power station G
i,i∈[1,l]Reactive power of
Value, active power
For wind-solar power station G
i,i∈[1,l]Real-time force is applied. The power flow of the feeder line is optimized, and the overall transmission capacity of the feeder line is improved. In step C12), calculating the wind-solar power station G
i,i∈[1,l]Operating power factor of
Time period t
j+1Internal active power
And reactive power
Is distributed to
Always holds as a constraint of the optimization algorithm, λ'
thrTo set the threshold value, λ'
thr>λ
thr. The working state of the wind and light power station is ensured to be at a better level, and excessive renewable energy waste is avoided.
D) Will be of period t
j+1Equally dividing the time into N small time periods, wherein the starting time t of each small time period
j+1|k,k∈[1,N]Node w
iCorresponding intelligent gateway
Read node w
iVoltage and frequency on, according to node w
iVoltage and frequency on, intelligent gateway
Wind-solar power station G
iOr energy storage station E
i,i∈[1,m]And performing power control, wherein m is the number of the energy storage stations. If node w
iConnected to wind-solar power station G
iThen, the following steps are executed: if node w
iWhen the voltage is lower than the standard value, the intelligent gateway
Controlling wind-solar power station G
iIncreasing reactive power
If node w
iIf the voltage is higher than the standard value, the intelligent gateway
Controlling wind-solar power station G
iReduction of reactive power
To output of (c). If node w
iConnected thereto is an energy storage station E
iThen, the following steps are executed: if node w
iWhen the voltage is lower than the standard value, the intelligent gateway
Controlling energy storage station E
iIncrease power output or decrease charging power if node w
iIf the voltage is higher than the standard value, the intelligent gateway
Controlling energy storage station E
iIncreasing the charging power or decreasing the discharging power.
As shown in fig. 3, D11) calculating wind-solar power station G
i,i∈[1,l]In real timeOutput force
Deviation from predicted value
Probability of deviation of
Tau is the rate of deviation and is the rate of deviation,
σ is the deviation rate τ | t
j+1The probability of occurrence; D12) time period t
j+1Internal and real-time monitoring wind-light power station G
i,i∈[1,l]Real-time force of
Deviation rate of (τ | t)
j+1If the probability of deviation is high
Then the energy storage station E is added
i,i∈[1,m]Charging power or reducing energy storage station E
i,i∈[1,m]Otherwise, the wind-light power station G is increased according to the set amplitude
i,i∈[1,l]Reactive power of output
Until real-time output
Deviation rate of (τ | t)
j+1Corresponding deviation probability
Fall back to sigma
thrThe following.
In step D11), the deviation probability is calculated
The method comprises the following steps: D111) counting wind-light power station G in each small period
i,i∈[1,l]Of real time forceMean value
r∈[1,N](ii) a D112) Will be of period t
j+1The former w time periods execute the step C11), and the wind-solar power station G in each small period in each time period is obtained
i,i∈[1,l]Mean value of real-time forces of
u∈[j-w,j],r∈[1,N](ii) a D113) Statistics of
The maximum value and the minimum value of (c),
section of will
Equally dividing the data into a plurality of value intervals, and respectively counting the data falling into each interval
Of each value interval
The ratio of the number of the wind-solar power station G to w.N is used as the wind-solar power station G
i,i∈[1,l]Real-time force of
Deviation probability corresponding to falling value interval
Short-term wind-solar power station G
i,i∈[1,l]The real-time output distribution probability has certain stability, when the real-time output is at a level with lower occurrence probability, the dispatching of the distribution network does not need to be adjusted by a large margin, and only the energy storage station needs to be used for balancing real-time output fluctuation in a short time.
In this embodiment, the access scheduling task can be completed only by acquiring the corresponding state data of the node through the monitoring module 200, the phase monitoring module 400 and the frequency monitoring module 500, and the installation and expansion are convenient, so that the method is suitable for the access of the distributed power supply. When the proportion of the reactive power in the distribution network is large, the distributed power supply is dispatched to output partial reactive power, although partial benefits can be reduced, the power factor of the transformer can be effectively improved, the stability of the microgrid is improved, the cost of newly adding the traditional energy source for adapting to the access of the renewable energy source is obviously reduced, and the distributed power supply dispatching method is suitable for dispatching the microgrid with the renewable energy source with high permeability.
Example two:
in this embodiment, a further improvement is made on the basis of the first embodiment, in this embodiment, in the step D), the energy storage station E is controlled
i,i∈[1,m]The method for increasing the charging power or increasing the discharging power comprises the following steps: D21) computing energy storage station E
i,i∈[1,m]Total increased charging power of
Rho is a set margin coefficient, rho>1; D22) establishing an evaluation function
Where z represents the number of small cycles,
for feeder i during time period t
j+1The average load of the z-th small period of time,
h is the number of feeders, i is the upper limit of the load of the feeder i; D23) at a set time before the beginning of the z-th small period, the wind-light power station G within the (z-1) th small period to the current time
iReal-time force of
Mean value calculation of
A value of (d); D24) obtaining an opinion using an optimization algorithmFunction of price
Energy storage station E with the smallest value
i,i∈[1,m]The charging power is increased in real time, and the process returns to step D23) at a predetermined timing before the start of the next small cycle. When the optimization algorithm runs, the transformer load limitation, the feeder flow limitation and the distributed power output upper limit are taken as limiting conditions, which are known in the art and are not described herein again. Compared with the first embodiment, the embodiment provides the small-period local power control through the intelligent gateway, and the operation safety and the comprehensive energy utilization efficiency of the micro-grid are further improved.
The above-described embodiments are only preferred embodiments of the present invention, and are not intended to limit the present invention in any way, and other variations and modifications may be made without departing from the spirit of the invention as set forth in the claims.