Control method and device for active power of wind power plant cluster

A control method for active power of a wind power plant cluster, wherein the wind power plant cluster comprises wind power plants of m priorities, wherein m is a positive integer and the control method comprises:

• monitoring a consumption capability of a power grid in real time, and determining an object active power of the wind power plant cluster according to the consumption capability of the power grid;
• determining a command for the active power of a wind power plant within each of the priorities according to the object active power of the wind power plant cluster in a descending order of the priorities;
• and
• controlling the active power of the wind power plant within the each of the priorities according to the command for the active power;
• wherein before monitoring the consumption capability of the power grid in real time, and determining the object active power of the wind power plant cluster according to the consumption capability of the power grid, the control method further comprises:
• presetting a priority j for each of the wind power plants in the wind power plant cluster, wherein j=1, 2, . . . , m, the priority of the each of the wind power plants is regularly updated;
• and n wind power plants are comprised in a same priority, wherein n is a positive integer;
• wherein the monitoring the consumption capability of the power grid in real time and determining the object active power of the wind power plant cluster according to the consumption capability of the power grid comprises:
• monitoring the consumption capability of the power grid in real time, and determining an object active power of the wind power plant cluster within (t+1) periods according to a consumption capability of the power grid at the end of t periods, wherein t is a positive integer;
• wherein a step of determining command active power of the wind power plant within the each of the priorities according to the object active power of the wind power plant cluster in a descending order of the priorities comprises:
• setting an object active power threshold;
• and controlling the command active power of the wind power plant within each of the priorities to be equal to 0 if the object active power of the wind power plant cluster is less than or equal to the object active power threshold;
• computing the command active power of each wind power plant within each of the priorities according to the following steps if the object active power of the wind power plant cluster is greater than the object active power threshold;
• step 1:
• for a wind power plant i within a j-th priority, computing an initial command active power corresponding to the wind power plant i according to the following formula:
• P1i,t+1ref=P1i,treal+ΔPi, i∈Nj, i=1,2, . . . n, j=1,2, . . . m;
• wherein P1i,t+1ref is the initial command active power of the wind power plant i in the j-th priority within the (t+1) period, and P1i,treal is a real active power of the wind power plant i in the j-th priority at the end of the t periods;
• ΔPi is a command step length of the wind power plant i in the j-th priority, and Nj is the j-th priority;
• step 2:
• computing a remaining object active power of wind power plants within a priority behind the priority according to the following formula after initial command active powers of all the wind power plants within the priority are computed:
• P
• j
• +
• 1
• ,
• t
• +
• 1
• obj
• =
• P
• t
• +
• 1
• obj
• -
• ∑
• i
• ∈
• N
• 1
• ⋃
• N
• 2
• ⋃
• …
• ⋃
• N
• j
• ⁢
• P
• ⁢
• ⁢
• 1
• i
• ,
• t
• +
• 1
• ref
• ,
• ⁢
• i
• ∈
• Nj
• ,
• i
• =
• 1
• ,
• 2
• ,
• …
• ⁢
• ⁢
• n
• ,
• j
• =
• 1
• ,
• 2
• ,
• …
• ⁢
• ⁢
• m
• ;
• wherein Pj+1,t+1obj is the remaining object active power of the wind power plants within the priority behind the j-th priority;
• Pt+1obj is the object active power of the wind power plant cluster;
• and
• ∑
• i
• ∈
• N
• 1
• ⋃
• N
• 2
• ⋃
• …
• ⋃
• N
• j
• ⁢
• P
• ⁢
• ⁢
• 1
• i
• ,
• t
• +
• 1
• ref
• is a sum of initial command active powers of all the wind power plants within the j-th priority and priorities before the j-th priority;
• step 3:
• comparing the remaining object active power Pj+1,t+1obj of the wind power plants of the priority behind the j-th priority with the sum
• ∑
• i
• ∈
• N
• j
• +
• 1
• ⁢
• P
• ⁢
• ⁢
• 1
• i
• ,
• t
• +
• 1
• ref
• of the initial command active powers of all the wind power plants within the (j+1)-th priority, controlling the command active power of the wind power plants behind the (j+1)-th priority to be 0 if
• P
• j
• +
• 1
• ,
• t
• +
• 1
• obj
• ≤
• ∑
• i
• ∈
• N
• j
• +
• 1
• ⁢
• P
• ⁢
• ⁢
• 1
• i
• ,
• t
• +
• 1
• ref
• ;
• and determining a first command active power of each of the wind power plants within the (j+1)-th priority according to the following formula:
• P
• ⁢
• ⁢
• 1
• i
• ,
• t
• +
• 1
• ref
• ′
• =
• P
• ⁢
• ⁢
• 1
• i
• ,
• t
• +
• 1
• ref
• ∑
• i
• ∈
• N
• j
• +
• 1
• ⁢
• ⁢
• P
• ⁢
• ⁢
• 1
• i
• ,
• t
• +
• 1
• ref
• ×
• P
• j
• +
• 1
• ,
• t
• +
• 1
• obj
• ,
• ,
• ⁢
• i
• ∈
• Nj
• +
• 1
• ⁢
• ,
• i
• =
• 1
• ,
• 2
• ,
• …
• ⁢
• ⁢
• n
• ,
• j
• =
• 1
• ,
• 2
• ,
• …
• ⁢
• ⁢
• m
• wherein P1i,t+1ref′ is the first command active power of the wind power plant i within the (j+1)-th priority;
• P1i,t+1ref is an initial command active power of the wind power plant i within the (j+1)-th priority;
• ∑
• i
• ∈
• N
• j
• +
• 1
• ⁢
• P
• ⁢
• ⁢
• 1
• i
• ,
• t
• +
• 1
• ref
• is the sum of initial command active powers of all the wind power plants within the (j+1)-th priority;
• and Pj+1,t+1obj is the remaining object active power of the wind power plants of the priority behind the j-th priority;
• and
• step 4:
• controlling the active power of each of the wind power plants within the j-th priority and the priority before the j-th priority to be equal to the initial command active power;
• and controlling the command active power of each of the wind power plants within the (j+1)-th priority to be equal to a first command active power, as shown in the following formulas:
• Pi,t+1ref=P1i,t+1ref;
• i∈N1 . . . Nj, i=1,2, . . . n;
• Pi,t+1ref=P1i,t+1ref′;
• i∈Nj+1, i=1,2, . . . n,
• wherein Pi,t+1ref is the command active power of the wind power plant i.