CN113346563B - Wind-solar hydrogen storage alternating-current and direct-current hybrid power distribution energy route control method - Google Patents

Abstract

The invention relates to a wind-solar hydrogen storage alternating current-direct current hybrid power distribution energy route control method, which comprises the following steps: step 1, obtaining static data and operation data, calculating an available conversion power coefficient of each VSC, selecting a numerical value with the minimum numerical value, assuming that a subscript corresponding to the numerical value is m, taking VSCm as a master control VSC, and establishing direct-current network voltage; the rest VSCs are used as slave stations for receiving power scheduling; step 2, solving the balance factor, and determining the power increment of each VSC based on the balance factor; and 3, when judging whether the adjustable load exists in the direct current bus, performing coordination control on each VSC according to the corresponding condition: when the adjustable load is not in the direct current bus, each VSC is subjected to fine adjustment; when the direct current bus has the adjustable load, the direct current hydrogen production load is adjusted according to the voltage of the direct current bus. The method is beneficial to the operation control and energy management of the wind-solar hydrogen storage alternating current-direct current hybrid power distribution system, and can effectively cope with abnormal conditions such as alternating current system faults.

Description

Wind-solar hydrogen storage alternating-current and direct-current hybrid power distribution energy route control method

Technical Field

The invention relates to the field of electric power, in particular to a wind-solar hydrogen storage alternating current-direct current hybrid power distribution energy route control method.

Background

In alpine regions in northern China, such as Zhang Jiakou in Hebei, Liaoning gourd island and the like, renewable energy sources such as solar energy, wind energy and the like are widely distributed and rich in resources, and meanwhile, under a normalized low-temperature environment, unique technical advantages such as long continuous journey and low energy consumption of hydrogen fuel automobiles and hydrogen energy public transportation are increasingly prominent, so that the renewable energy sources become important carriers and key links of new energy green transportation industry in alpine and high-altitude cities. The comprehensive system of wind-solar complementary power generation hydrogen production-hydrogen storage-hydrogen utilization organically fuses hydrogen energy and renewable energy sources, hydrogen production is carried out at low cost as a support, the phenomena of full consumption of the renewable energy sources, wind limitation and light abandonment and the like can be improved, and meanwhile, the overall economy can be obviously enhanced through multi-energy complementation. The wind/light complementary hydrogen production technology becomes one of the important directions for clean energy transformation and the cultivation of new economic growth points.

Fig. 1 depicts a typical configuration of a wind, light and hydrogen storage AC/dc hybrid power distribution system, wherein a single AC system AC is interconnected to a dc network via a voltage-source converter (VSC), wherein AC sides of VSC1, …, VSC2, …, VSCn are connected to AC1, …, AC2, …, ACn, respectively, while dc sides of VSC1, …, VSC2, …, VSCn are connected to dc busbars via dc lines. The direct current network can integrate photovoltaic power generation, wind power generation, an energy storage device, a hydrogen production load and the like, and when the direct current voltage of equipment is not matched with the voltage level of a direct current bus, a corresponding DC/DC converter can be configured for adaptation.

When wind-solar hydrogen storage alternating current-direct current hybrid power distribution runs, partial alternating current system faults or overhauling and other conditions can occur, when a certain alternating current system breaks down, the connected VSC is switched into an alternating current constant frequency constant voltage control strategy, and when the condition occurs, if the VSC is a main station (namely, a constant direct current voltage control strategy is adopted), the VSC cannot continuously support direct current voltage, so that the system cannot normally work. Therefore, other VSC regulation control strategies and operation points need to be coordinated to ensure that renewable energy sources complement and stably produce hydrogen. Based on the method, the invention provides a wind-solar hydrogen storage alternating current-direct current hybrid power distribution energy route control method.

Wind-solar hydrogen storage alternating current-direct current hybrid power distribution system may have abnormal conditions such as alternating current system faults, especially when an alternating current system accessed by a main station VSC has faults, the alternating current system is switched into an alternating current constant frequency and constant voltage control strategy, the constant direct current voltage control strategy cannot be continuously adopted to effectively support direct current voltage, and the abnormal state of the system is caused.

Disclosure of Invention

In order to solve the technical problems, the invention provides a wind-solar-hydrogen storage alternating-current-direct-current hybrid power distribution energy route control method, which is used for quickly selecting a new master station to establish direct-current network voltage and adjusting the operating points of the remaining VSCs to ensure complementary stable hydrogen production of renewable energy sources and system optimized operation.

The technical scheme of the invention is as follows: a wind-solar hydrogen storage alternating current-direct current hybrid power distribution energy route control method comprises the following steps:

step 1, obtaining static data and operation data, calculating an available conversion power coefficient of each VSC, selecting a numerical value with the minimum numerical value, assuming that a subscript corresponding to the numerical value is m, taking VSCm as a master control VSC, and establishing direct-current network voltage; the rest VSCs are used as slave stations for receiving power scheduling;

step 2, solving the balance factor, and determining the power increment of each VSC based on the balance factor;

and 3, when judging whether the adjustable load exists in the direct current bus, performing coordination control on each VSC according to the corresponding condition: when the adjustable load is not in the direct current bus, each VSC is subjected to fine adjustment; when the direct current bus has an adjustable load, adjusting the direct current hydrogen production load according to the voltage of the direct current bus;

further, the step 1 of acquiring static data and operating data specifically includes:

obtaining VSC1 rated capacity S_r,1Rated capacity S of VSCn_r,nVSCN rated capacity S_r,N(ii) a N is the total number of VSCs, and N is any integer from 1 to N.

Obtaining rated capacity S of transformer of alternating current system accessed by VSC1_T,1Rated capacity S of transformer of AC system to which VSCn is connected_T,nRated capacity S of transformer of AC system to which VSCN is connected_T,N；

Obtaining VSC1 active power P at current operation time₁VSC1 reactive power Q at current running time₁VSCn active power P at the current operating time_nVSCn reactive power Q at the current operating time_nThe VSCN active power P of the current running time_NVSCN reactive power Q of current running time_N；

Obtaining the load active power P of the AC system accessed by the VSC1 at the current operation time_ac,1And acquiring the load reactive power Q of the alternating current system accessed by the VSC1 at the current running time_ac,1(ii) a Obtaining the load active power P of the AC system accessed by the VSCn at the current operation time_ac,nObtaining the load reactive power Q of the AC system accessed by the VSCn at the current operation time_ac,n(ii) a Obtaining a currentLoad active power P of alternating current system accessed by VSCN at running time_ac,NObtaining the load reactive power Q of the AC system accessed by the VSCN at the current running time_ac,N。

Further, the calculating the available conversion power coefficient of each VSC in step 1 specifically includes: calculating available conversion power coefficient A of nth VSC_n：

A₁＝((P₁+P_ac,1)²+(Q₁+Q_ac,1)²)/(S_T,1)²+(1-P₁/max(S_r,1…S_r,n…S_r,N))²+((P₁)²+

(Q₁)²)/(max(S_r,1…S_r,n…S_r,N))²

A₁＝sqrt(A₁)

A_n＝((P_n+P_ac,n)²+(Q_n+Q_ac,n)²)/(S_T,n)²+(1-P_n/max(S_r,1…S_r,n…S_r,N))²+((P_n)²+

(Q_n)²)/(max(S_r,1…S_r,n…S_r,N))²

A_n＝sqrt(A_n)

A_N＝((P_N+P_ac,N)²+(Q_N+Q_ac,N)²)/(S_T,N)²+(1-P_N/max(S_r,1…S_r,n…S_r,N))²+((P_N)²+

(Q_N)²)/(max(S_r,1…S_r,n…S_r,N))²

A_N＝sqrt(A_N)

Selection A_1…A_n…A_NIf the subscript corresponding to the numerical value with the minimum numerical value is assumed to be m, the VSCm serves as a master control VSC, and direct-current network voltage is established; the rest are eachThe VSC then receives power scheduling as a slave.

Further, in the step 2, the balance factor is solved, and based on the balance factor, the power increment of each remaining VSC is determined, and the balance factor B is calculated as follows:

B＝((P₁+P_ac,1)²+(Q₁+Q_ac,1)²+…+(P_n+P_ac,n)²+(Q_n+Q_ac,n)²+…+(P_N+P_ac,N)²+(Q_N+

Q_ac,N)²)/((S_T,1)²+…+(S_T,n)²+…+(S_T,N)²)

B＝sqrt(B)

the power increment of the nth VSC is:

ΔP_n＝sqrt((S_T,nB)²-(Q_n+Q_ac,n)²)-P_ac,n-P_n

where n is not equal to m.

Further, in step 3, when there is no adjustable load in the dc bus, each VSC performs fine adjustment:

the power increment of the nth VSC is delta P_nWhere n is not equal to m, when (P)_n+ΔP_n)²+(Q_n)²>(S_r,n)²When the temperature of the water is higher than the set temperature,

ΔP_n＝sqrt((S_r,n)²-(P_n)²-(Q_n)²)-P_n。

further, in the step 3, when the direct current bus has the adjustable load,

judging if the DC bus voltage U is>U_H: then the load of the direct current hydrogen production is increased as follows:

min{min(ΔP₁,…ΔP_n,…ΔP_N)(N-1),sqrt((S_r,m)²-(P_m)²-(Q_m)²)-P_m,P_f,max}

judging if the DC bus voltage U is<U_L: then the reduction of the direct current hydrogen production load is:

min{|max(ΔP₁,…ΔP_n,…ΔP_N)(N-1)|,P_m,P_f,max}

wherein U is_HIs the upper limit value, U, of the DC bus voltage_LIs the lower limit, P, of the DC bus voltage_f,maxIs an adjustable load limit.

Has the advantages that:

(1) the invention provides a wind-solar hydrogen storage alternating current-direct current hybrid power distribution energy route control method, which can effectively make up for the existing defects, is beneficial to the operation control and energy management of a wind-solar hydrogen storage alternating current-direct current hybrid power distribution system, effectively deals with abnormal conditions such as alternating current system faults and the like, and has wide application prospect.

(2) The method provided by the invention mainly combines the power regulation of VSC and the power regulation of hydrogen production load, thereby greatly improving the energy utilization efficiency.

Drawings

FIG. 1 is a schematic diagram of a wind-solar-hydrogen storage AC-DC hybrid power distribution system;

FIG. 2 is a flow chart of the method of the present invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be described clearly and completely with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, rather than all embodiments, and all other embodiments obtained by a person skilled in the art based on the embodiments of the present invention belong to the protection scope of the present invention without creative efforts.

According to an embodiment of the present invention, a method for controlling a route of wind, light, hydrogen, alternating current and direct current hybrid power distribution energy is provided, as shown in fig. 2, the method includes the following steps:

step 1, obtaining static data and operation data, calculating an available conversion power coefficient of each VSC, selecting a numerical value with the minimum numerical value, assuming that a subscript corresponding to the numerical value is m, taking VSCm as a master control VSC, and establishing direct-current network voltage; the rest VSCs are used as slave stations for receiving power scheduling;

step 2, solving the balance factor, and determining the power increment of each VSC based on the balance factor;

and 3, when judging whether the adjustable load exists in the direct current bus, performing coordination control on each VSC according to the corresponding condition: when the adjustable load is not in the direct current bus, each VSC is subjected to fine adjustment; when the direct current bus has the adjustable load, the direct current hydrogen production load is adjusted according to the voltage of the direct current bus.

Specifically, the steps are as follows:

step 1, acquiring static data and operating data, calculating an available conversion power coefficient of each VSC, selecting a numerical value with the minimum numerical value, assuming that a subscript corresponding to the numerical value is m, taking VSCm as a master control VSC, and establishing direct-current network voltage; and the rest VSCs are used as slave stations for receiving power scheduling. The method specifically comprises the following steps:

obtaining VSC1 rated capacity S_r,1Rated capacity S of VSCn_r,nVSCN rated capacity S_r,N(ii) a N is the total number of VSCs, and N is any integer from 1 to N.

Obtaining rated capacity S of transformer of alternating current system accessed by VSC1_T,1Rated capacity S of transformer of AC system to which VSCn is connected_T,nRated capacity S of transformer of AC system to which VSCN is connected_T,N；

Obtaining VSC1 active power P at current operation time₁VSC1 reactive power Q at current running time₁VSCn active power P at the current operating time_nVSCn reactive power Q at the current operating time_nThe VSCN active power P of the current running time_NVSCN reactive power Q of current running time_N；

Obtaining the load active power P of the AC system accessed by the VSC1 at the current operation time_ac,1And acquiring the load reactive power Q of the alternating current system accessed by the VSC1 at the current running time_ac,1(ii) a Obtaining the load active power P of the AC system accessed by the VSCn at the current operation time_ac,nObtaining the load reactive power Q of the AC system accessed by the VSCn at the current operation time_ac,n(ii) a Obtaining the AC system accessed by the VSCN at the current operating timeLoad active power P_ac,NObtaining the load reactive power Q of the AC system accessed by the VSCN at the current running time_ac,N；

Calculating available conversion power coefficient A of nth VSC_n：

A₁＝((P₁+P_ac,1)²+(Q₁+Q_ac,1)²)/(S_T,1)²+(1-P₁/max(S_r,1…S_r,n…S_r,N))²+((P₁)²+

(Q₁)²)/(max(S_r,1…S_r,n…S_r,N))²

A₁＝sqrt(A₁)

A_n＝((P_n+P_ac,n)²+(Q_n+Q_ac,n)²)/(S_T,n)²+(1-P_n/max(S_r,1…S_r,n…S_r,N))²+((P_n)²+

(Q_n)²)/(max(S_r,1…S_r,n…S_r,N))²

A_n＝sqrt(A_n)

A_N＝((P_N+P_ac,N)²+(Q_N+Q_ac,N)²)/(S_T,N)²+(1-P_N/max(S_r,1…S_r,n…S_r,N))²+((P_N)²+

(Q_N)²)/(max(S_r,1…S_r,n…S_r,N))²

A_N＝sqrt(A_N)

Selection A_1…A_n…A_NAnd (3) assuming that the subscript corresponding to the numerical value with the minimum median value is m, taking the VSCm as the master control VSC, and establishing the direct current network voltage. And the rest VSCs are used as slave stations for receiving power scheduling.

Step 2, solving the balance factor, determining the power increment of each VSC based on the balance factor, and calculating the balance factor B as follows:

B＝((P₁+P_ac,1)²+(Q₁+Q_ac,1)²+…+(P_n+P_ac,n)²+(Q_n+Q_ac,n)²+…+(P_N+P_ac,N)²+(Q_N+

Q_ac,N)²)/((S_T,1)²+…+(S_T,n)²+…+(S_T,N)²)

B＝sqrt(B)

power increment of the nth VSC (n not equal to m):

ΔP_n＝sqrt((S_T,nB)²-(Q_n+Q_ac,n)²)-P_ac,n-P_n

when judging that there is adjustable load in the direct current bus, according to the condition that corresponds, carry out coordinated control to each VSC:

when the adjustable load is not in the direct current bus, each VSC is subjected to fine adjustment; when the direct current bus has the adjustable load, the direct current hydrogen production load is adjusted according to the voltage of the direct current bus. Specifically, the method comprises the following steps:

step 3, when no adjustable load exists in the direct current bus, each VSC is subjected to fine adjustment:

the power increment of the nth VSC (n is not equal to m) is delta P_nWhen (P)_n+ΔP_n)²+(Q_n)²>(S_r,n)²When the temperature of the water is higher than the set temperature,

ΔP_n＝sqrt((S_r,n)²-(P_n)²-(Q_n)²)-P_n

step 4 when the direct current bus has adjustable load,

4.1 judging if the DC bus voltage U>U_H: then the load of the direct current hydrogen production is increased as follows:

min{min(ΔP₁,…ΔP_n,…ΔP_N)(N-1),sqrt((S_r,m)²-(P_m)²-(Q_m)²)-P_m,P_f,max}

4.2 judging if the DC bus voltage U<U_L: then the reduction of the direct current hydrogen production load is:

min{|max(ΔP₁,…ΔP_n,…ΔP_N)(N-1)|,P_m,P_f,max}

wherein U is_HIs the upper limit value, U, of the DC bus voltage_LIs the lower limit, P, of the DC bus voltage_f,maxIs an adjustable load limit.

Compared with the prior art, the method provided by the invention mainly combines the power regulation of the VSC and the power regulation of the hydrogen production load, and the energy utilization efficiency is greatly improved.

The wind/light complementary hydrogen production technology becomes one of the important directions for clean energy transformation and the cultivation of new economic growth points. The invention provides a wind-solar hydrogen storage alternating current-direct current hybrid power distribution energy route control method, which can effectively make up for the existing defects, is beneficial to the operation control and energy management of a wind-solar hydrogen storage alternating current-direct current hybrid power distribution system, effectively deals with abnormal conditions such as alternating current system faults and the like, and has wide application prospect.

Although illustrative embodiments of the present invention have been described above to facilitate the understanding of the present invention by those skilled in the art, it should be understood that the present invention is not limited to the scope of the embodiments, but various changes may be apparent to those skilled in the art, and it is intended that all inventive concepts utilizing the inventive concepts set forth herein be protected without departing from the spirit and scope of the present invention as defined and limited by the appended claims.

Claims (3)

1. A wind-solar hydrogen storage alternating current-direct current hybrid power distribution energy route control method is characterized by comprising the following steps:

step 1, obtaining static data and operation data, calculating an available conversion power coefficient of each VSC, selecting a numerical value with the minimum numerical value, assuming that a subscript corresponding to the numerical value is m, taking VSCm as a master control VSC, and establishing direct-current network voltage; the rest VSCs are used as slave stations for receiving power scheduling;

step 2, solving the balance factor, and determining the power increment of each VSC based on the balance factor;

and 3, when judging whether the adjustable load exists in the direct current bus, performing coordination control on each VSC according to the corresponding condition: when the adjustable load is not in the direct current bus, each VSC is subjected to fine adjustment; when the direct current bus has an adjustable load, adjusting the direct current hydrogen production load according to the voltage of the direct current bus;

the step 1 of acquiring static data and operating data specifically includes:

obtaining VSC1 rated capacity S_r,1Rated capacity S of VSCn_r,nVSCN rated capacity S_r,N(ii) a N is the total number of VSCs, and N is any integer from 1 to N;

obtaining rated capacity S of transformer of alternating current system accessed by VSC1_T,1Rated capacity S of transformer of AC system to which VSCn is connected_T,nRated capacity S of transformer of AC system to which VSCN is connected_T,N；

Obtaining VSC1 active power P at current operation time₁VSC1 reactive power Q at current running time₁VSCn active power P at the current operating time_nVSCn reactive power Q at the current operating time_nThe VSCN active power P of the current running time_N,VSCN reactive power Q of current operation time_N；

Obtaining the load active power P of the AC system accessed by the VSC1 at the current operation time_ac,1And acquiring the load reactive power Q of the alternating current system accessed by the VSC1 at the current running time_ac,1(ii) a Obtaining the load active power P of the AC system accessed by the VSCn at the current operation time_ac,nObtaining the load reactive power Q of the AC system accessed by the VSCn at the current operation time_ac,n(ii) a Obtaining load active power P of alternating current system accessed by VSCN at current operation time_ac,NObtaining the load reactive power Q of the AC system accessed by the VSCN at the current running time_ac,N；

The calculating the available conversion power coefficient of each VSC in step 1 specifically includes: calculating available conversion power coefficient A of nth VSC_n：

A₁＝((P₁+P_ac,1)²+(Q₁+Q_ac,1)²)/(S_T,1)²+(1-P₁/max(S_r,1…S_r,n…S_r,N))²+((P₁)²+

(Q₁)²)/(max(S_r,1…S_r,n…S_r,N))²

A₁:＝sqrt(A₁)

Wherein, the value is assigned operation, and sqrt is evolution operation;

A_n＝((P_n+P_ac,n)²+(Q_n+Q_ac,n)²)/(S_T,n)²+(1-P_n/max(S_r,1…S_r,n…S_r,N))²+((P_n)²+

(Q_n)²)/(max(S_r,1…S_r,n…S_r,N))²

A_n:＝sqrt(A_n)

A_N＝((P_N+P_ac,N)²+(Q_N+Q_ac,N)²)/(S_T,N)²+(1-P_N/max(S_r,1…S_r,n…S_r,N))²+((P_N)²+

(Q_N)²)/(max(S_r,1…S_r,n…S_r,N))²

A_N:＝sqrt(A_N)

selection A_1…A_n…A_NIf the subscript corresponding to the numerical value with the minimum numerical value is assumed to be m, the VSCm serves as a master control VSC, and direct-current network voltage is established; the rest VSCs are used as slave stations for receiving power scheduling;

and 2, solving the balance factor, determining the power increment of each VSC based on the balance factor, and calculating the balance factor B as follows:

B＝((P₁+P_ac,1)²+(Q₁+Q_ac,1)²+…+(P_n+P_ac,n)²+(Q_n+Q_ac,n)²+…+(P_N+P_ac,N)²+(Q_N+

Q_ac,N)²)/((S_T,1)²+…+(S_T,n)²+…+(S_T,N)²)

B:＝sqrt(B)

the power increment of the nth VSC is:

ΔP_n＝sqrt((S_T,nB)²-(Q_n+Q_ac,n)²)-P_ac,n-P_n

where n is not equal to m.

2. The method for controlling the routing of the wind, light, hydrogen storage alternating current and direct current hybrid power distribution energy according to claim 1, wherein in the step 3, when no adjustable load exists in a direct current bus, each VSC performs fine adjustment:

the power increment of the nth VSC is delta P_nWhere n is not equal to m, when (P)_n+ΔP_n)²+(Q_n)²>(S_r,n)²When the temperature of the water is higher than the set temperature,

ΔP_n＝sqrt((S_r,n)²-(P_n)²-(Q_n)²)-P_n。

3. the method for controlling the routing of the wind, light, hydrogen storage AC and DC hybrid power distribution energy according to claim 1, wherein in the step 3, when the DC bus has an adjustable load,

judging if the DC bus voltage U is>U_H: then the load of the direct current hydrogen production is increased as follows:

min{min(ΔP₁,…ΔP_n,…ΔP_N)(N-1),sqrt((S_r,m)²-(P_m)²-(Q_m)²)-P_m,P_f,max}

judging if the DC bus voltage U is<U_L: then the reduction of the direct current hydrogen production load is:

min{|max(ΔP₁,…ΔP_n,…ΔP_N)(N-1)|,P_m,P_f,max}

wherein U is_HIs the upper limit value, U, of the DC bus voltage_LIs the lower limit, P, of the DC bus voltage_f,maxIs an adjustable load limit.

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