CN110676876A - Ultra-high voltage direct current correction method considering transmitting end and receiving end power grids - Google Patents

Abstract

The invention discloses an extra-high voltage direct current correction method considering a transmitting end power grid and a receiving end power grid, which comprises the following steps of: establishing an extra-high voltage direct current correction model objective function considering a new energy consumption space of a transmitting-end power grid and a peak regulation margin of a receiving-end power grid; establishing a constraint condition of the target function of the extra-high voltage direct current correction model; calculating and determining a corrected extra-high voltage direct current tie line power curve according to the extra-high voltage direct current correction model objective function and the constraint condition; and adjusting the power of the extra-high voltage direct current tie line according to the corrected power curve of the extra-high voltage direct current tie line. The invention considers that the sending end reduces the wind abandoning rate and the light abandoning rate, simultaneously reduces the peak load regulation pressure of the receiving end power grid, and ensures the stable operation of the receiving end power grid.

Description

Ultra-high voltage direct current correction method considering transmitting end and receiving end power grids

Technical Field

The invention relates to the technical field of electric power, in particular to an extra-high voltage direct current correction method considering a transmitting-end power grid and a receiving-end power grid.

Background

The new energy in China is distributed intensively and is in 'reverse distribution' with the load center, so that the new energy consumption is difficult. Therefore, the construction of an extra-high voltage direct current line to transmit the far-end clean energy to the load center, and the realization of large-scale and long-distance transmission of electric energy becomes a necessary choice for solving the unbalanced pattern of energy distribution in China.

At present, the direct current project which is put into operation in China mainly adopts a two-section operation mode, the electric power is constant in each time interval, namely a constant power mode, and a direct current operation plan curve is mainly in a straight line type. In a constant power mode, a power transmission plan is arranged according to the operation requirement of a power supply at a transmitting end under most conditions, so that a 'straight line' or even 'reverse peak regulation' plan is very easy to appear, peak regulation pressure is not relieved for a power grid at a receiving end, but the power grid at the receiving end has to passively absorb a large amount of low-valley power, the low-valley peak regulation contradiction of the power grid at the receiving end is aggravated, and the safe, economic and efficient operation of the power grid at the receiving end is not facilitated. Or optimizing the direct current operation mode by taking the optimal operation economy of the receiving-end power grid as a target to improve the peak shaving problem of the receiving-end power grid.

However, no extra-high voltage direct current correction method considering the requirements of a transmitting end and a receiving end simultaneously is found at present, a global optimization cannot be established for the whole transmitting and receiving end system, and actually, due to the fact that direct current operation has the characteristic that the transmission power is adjustable within a constraint range, if the randomness, the intermittence and the load change of a receiving end power grid are considered at the same time, the 'reverse peak regulation' plan of the receiving end power grid is prevented on the basis that the transmitting end power grid consumes wind power and photovoltaic power as much as possible. Therefore, how to establish a scientific, reasonable and fair optimization model and ensure the benefit balance of the transmitting end and the receiving end is a problem worthy of deep research.

Disclosure of Invention

The invention mainly aims to provide an extra-high voltage direct current correction method considering a transmitting end and a receiving end power grid, and aims to solve the problem that an extra-high voltage direct current correction method considering requirements of the transmitting end and the receiving end simultaneously does not exist in the prior art.

In order to achieve the purpose, the extra-high voltage direct current correction method for the power grid at the transmitting end and the receiving end comprises the following steps:

establishing an extra-high voltage direct current correction model objective function considering a new energy consumption space of a transmitting-end power grid and a peak regulation margin of a receiving-end power grid;

establishing constraint conditions of the target function of the extra-high voltage direct current correction model, wherein the constraint conditions comprise power generation-load power balance constraint, peak regulation capacity balance constraint, preset extra-high voltage direct current tie line correction power constraint, extra-high voltage direct current tie line transaction electric quantity constraint, end power grid load constraint and end power grid peak regulation margin correlation constraint, and end power grid water-heat power generation unit peak regulation constraint;

calculating and determining a corrected extra-high voltage direct current tie line power curve according to the extra-high voltage direct current correction model objective function and the constraint condition;

and adjusting the power of the extra-high voltage direct current tie line according to the corrected power curve of the extra-high voltage direct current tie line.

Preferably, the step of establishing an extra-high voltage direct current correction model objective function considering a new energy consumption space of a transmitting-end power grid and a peak regulation margin of a receiving-end power grid includes:

acquiring preset correction power of the extra-high voltage direct-current connecting line, wind and light abandoning cost of a sending-end power grid, extra-high voltage direct-current connecting line power before correction, sending-end power grid load, peak shaving cost of a receiving-end power grid, receiving-end power grid load, output power of a new energy source unit of the receiving-end power grid and minimum output power of a water-fire motor unit of the receiving-end power grid;

determining an increased new energy consumption space according to the preset extra-high voltage direct current tie line correction power, the extra-high voltage direct current tie line power before correction and the sending end power grid load;

determining the peak reduction margin of the receiving-end power grid according to the receiving-end power grid load, the output power of the new energy unit of the receiving-end power grid and the minimum output power of the hydro-thermal generator unit of the receiving-end power grid;

and establishing the target function of the extra-high voltage direct current correction model according to the wind and light abandoning cost of the transmitting-end power grid, the added new energy consumption space, the peak regulation cost of the receiving-end power grid and the peak regulation margin of the receiving-end power grid.

Preferably, the added new energy consumption space is determined by using the following calculation formula:

P_g,t＝P_LU,t-P_line,t；

P′_g,t＝P_LU,t-P_line,t-ΔP_line,t；

Q_t＝P′_g,t-P_g,t；

in the formula, Q_tNew energy consumption space, P, added for t moment of sending end power grid_g,tTo correct the original equivalent load, P ', of the frontend grid at time t'_g,tFor correcting the original equivalent load at time t of the back-end grid, P_LU,tA power supply terminal at time tNetwork load, P_line,tIs the power of the extra-high voltage DC tie line at the time t, delta P_line,tAnd presetting the correction power of the extra-high voltage direct current tie line at the time t.

Preferably, the following calculation formula is adopted for calculating the peak regulation margin of the receiving-end power grid:

P_YD,i,t＝P_LD,i,t-P_GU,min,i,t-P_NED,i,t-P_line,i,t；

in the formula, P_YD,i,tThe peak regulation margin P of the ith receiving end power grid at the moment t_GU,min,i,tThe minimum output power P of the ith receiving end power grid water-fire electric generator set at the moment t_LD,i,tLoad of receiving end power grid system at time t, P_NED,i,tThe minimum output power P of the wind power and photovoltaic generator set at the ith receiving end power grid at the moment t_line,i,tThe power of the ith extra-high voltage direct current tie line at the moment t.

Preferably, the target function of the extra-high voltage direct current correction model is as follows:

wherein,

P′_YD,i,t＝P_LD,i,t-P′_GU,min,i,t-P_NED,i,t-P_line,i,t-ΔP_line,i,t；

of formula (II) to (III)'_YD,i,tThe ith receiving grid is the peak regulation margin at the time t after correction, P'_GU,min,i,tThe minimum output power C of the hydro-thermal power generation unit at the moment t of the ith receiving-end power grid after preset correction₁Peak shaving cost for the receiving grid, C₂Light and wind abandoning cost for the sending-end power grid, M_tAnd F is the reduced peak shaving cost of the power grid system at the receiving end at the moment t.

Preferably, the constraint on the correlation between the load of the receiving-end power grid and the peak shaving margin of the receiving-end power grid is as follows:

wherein,

and the Pearson correlation coefficient represents the corrected load of the receiving end power grid of the ith receiving end power grid and the minimum output power of the power supply of the receiving end power grid, and N is a preset value related to cost.

Preferably, the constraints of the extra-high voltage direct current tie line power include constraints of an extra-high voltage direct current tie line power regulation rate and constraints of an extra-high voltage direct current tie line power regulation range;

wherein, the power regulation rate constraint of the extra-high voltage direct current tie line is as follows:

|(P_line,i,t+ΔP_line,i,t)-(P_line,i,t-1+ΔP_line,i,t-1)|≤U_Zi；

in the formula of U_ZiFor the maximum regulation rate, P, of the ith extra-high voltage DC tie line power_line,i,tThe power, delta P, of the ith extra-high voltage DC link at time t_line,i,tCorrecting power for preset extra-high voltage direct current tie line of ith extra-high voltage direct current tie line at time t, P_line,i,t-1The ultra-high voltage direct current tie line power, delta P, of the ith ultra-high voltage direct current tie line at the time t-1_line,i,t-1Correcting power for a preset extra-high voltage direct current tie line of the ith extra-high voltage direct current tie line at the time of t-1;

the extra-high voltage direct current tie line power regulation range constraint is as follows:

P_Simin≤P_line,i,t+ΔP_line,i,t≤P_Simax；

in the formula, P_SimaxThe power safety upper limit, P, of the ith extra-high voltage direct current tie line_SiminAnd the power safety lower limit of the extra-high voltage direct current tie line of the ith extra-high voltage direct current tie line is set.

Preferably, the power generation-load power balance constraint comprises: the method comprises the following steps of carrying out power generation-load power balance constraint on a transmitting-end power grid and carrying out power generation-load power balance constraint on a receiving-end power grid;

wherein, the power generation-load power balance constraint of the sending end power grid is as follows:

P_G,t+P'_NE,t＝P_L,t+P_line,t+ΔP_line,t；

in the formula, P_line,tIs the power of the extra-high voltage DC tie line at the time t, delta P_line,tPresetting extra-high voltage DC tie line correction power P for time t_G,tIs the power of a hydro-thermal generator set of a transmission end grid at time t'_NE,tPresetting the power P of the wind power and the photovoltaic generator set for a transmitting end power grid at the moment t_L,tSending end power grid load at time t;

the power generation-load power balance constraint of the receiving-end power grid is as follows:

P'_G,i,t+P_NE,i,t+P_line,i,t+ΔP_line,i,t＝P_L,i,t；

of formula (II) to (III)'_G,i,tThe power P of a preset receiving-end power grid hydro-thermal generator set of the ith receiving-end power grid at the moment t_L,i,tReceiving end power grid load P of ith receiving end power grid at time t_NE,i,tThe power P of the wind power generation unit and the photovoltaic generator set of the ith receiving end power grid at the moment t_line,i,tThe power, delta P, of the ith extra-high voltage DC link at time t_line,i,tAnd correcting the power of the preset extra-high voltage direct current tie line of the ith extra-high voltage direct current tie line at the time t.

Preferably, the constraints of peak shaving capacity balance include: peak regulation capacity balance constraint of a sending end power grid and peak regulation capacity balance constraint of the sending end power grid;

the peak regulation capacity balance constraint of the power grid at the sending end is as follows:

H_U> 0 and L_UThe conditions are satisfied at the same time when the pressure is greater than 0,

wherein,

H_U＝P_GUmax-P_lineHU-ΔP_lineHU-P'_LUmax-P_RHU；

L_U＝P'_LUmin+P_lineLU+ΔP_lineLU-P_GminU-P_RLU；

in the formula, H_uThe peak regulation margin L on the transmission end power grid at the peak load period of the transmission end power grid_UFor the sending end power grid down-regulation peak margin, P, in the low peak period of the sending end power grid load_GUmaxThe maximum output power, P, can be adjusted for the water-fire electric generator set of the sending end power grid in the peak load period of the sending end power grid_lineHUFor the power, delta P, of the extra-high voltage direct-current tie line during the peak load period of the transmission-end power grid_lineHUPresetting correction power P 'of extra-high voltage direct current tie line for transmission-end power grid in load peak period of transmission-end power grid'_LUmaxThe maximum equivalent load P is the typical daily load of the sending end power grid minus the new energy output power of the sending end power grid_RHUReserve capacity, P ', for a sending-side grid during peak load periods of the sending-side grid'_LUminThe minimum output power, P, can be adjusted for the water-fire electric generator set of the power grid at the load bottom peak period of the power grid at the sending end_lineLUIs the ultra-high voltage direct current tie line power, delta P, of the power grid at the load bottom peak period of the power grid at the sending end_lineLUPresetting extra-high voltage direct current tie line correction power for transmission end power grid in load bottom peak period of transmission end power grid_GminUThe minimum equivalent load P of the typical daily load of the sending-end power grid minus the new energy output power of the sending-end power grid_RLUThe reserve capacity is the reserve capacity in the load low peak period of the power grid at the sending end;

the peak regulation capacity balance constraint of the sending end power grid is as follows:

H_D> 0 and L_DThe conditions are satisfied at the same time when the pressure is greater than 0,

wherein,

H_D＝P_GDmax+P_lineHD+ΔP_lineHD-P'_LDmax-P_RHD；

L_D＝P'_LDmin-P_GDmin-P_lineLD-ΔP_lineLD-P_RLD；

in the formula, H_DThe peak up-regulation margin P of the receiving-end power grid in the peak load period of the receiving-end power grid_GDmaxTo be atMinimum output power, P, of receiving-end power grid hydro-thermal generator set in load bottom peak period of receiving-end power grid_lineHDIs the extra-high voltage direct current tie line power, delta P, of the receiving-end power grid in the load bottom peak period of the receiving-end power grid_lineHDPresetting correction power P 'of extra-high voltage direct current tie line for receiving-end power grid in load bottom peak period of receiving-end power grid'_LDmaxThe minimum equivalent load, P, of the typical daily load of the receiving-end power grid minus the wind power photovoltaic output power of the receiving-end power grid_RHDReserve capacity, L, for the receiving end grid during low peak periods of receiving end grid load_DFor the receiving end power grid under-regulation peak margin in the receiving end power grid load peak period, P_GDminThe minimum output power, P, of the receiving-end power grid hydro-thermal generator set in the load bottom peak period of the receiving-end power grid can be adjusted_lineLDIs the extra-high voltage direct current tie line power, delta P, of the receiving end power grid in the load bottom peak period of the receiving end power grid_lineLDPresetting correction power P 'of extra-high voltage direct current tie line for receiving-end power grid in load bottom peak period of receiving-end power grid'_LDminThe minimum equivalent load, P, of the typical daily load of the receiving-end power grid minus the wind power photovoltaic output power of the receiving-end power grid_RLDAnd the standby capacity of the receiving end power grid in the low peak load period of the receiving end power grid is obtained.

Preferably, the establishing of the constraint of the correction power of the preset extra-high voltage direct current tie line, the constraint of the transaction electric quantity of the extra-high voltage direct current tie line and the peak regulation constraint of the water-power-generation unit of the receiving-end power grid is as follows:

wherein, the preset extra-high voltage direct current tie line modified power constraint is as follows:

-P_line,t≤ΔP_line,t≤P_NEU,max,t-P_line,t；

in the formula,. DELTA.P_line,tCorrecting the power for the preset extra-high voltage DC link at time t, P_line,tFor extra-high voltage DC link power at time t, P_NEU,max_,tThe maximum possible output power of the wind-solar unit of the power grid at the sending end is obtained;

the extra-high voltage direct current connecting line transaction electric quantity constraint is as follows:

in the formula, E_Z,i,maxFor the maximum transaction electric quantity of the ith extra-high voltage direct current connecting line in a planning period T, E_Z,i,minFor the minimum transaction electric quantity of the ith extra-high voltage direct current connecting line in the planning period T,

for the transaction electric quantity of the ith extra-high voltage direct current connecting line in the planning period T, P_line,i,tThe power, delta P, of the ith extra-high voltage DC link at time t_line,i,tCorrecting power for a preset extra-high voltage direct current tie line of the ith extra-high voltage direct current tie line at the time t;

the power constraint of the receiving-end power grid water-fire electric generator set is as follows:

P_Gmin,i,t≤P'_G,i,t≤P_Gmax,i,t；

|P'_G,i,t-P'_G,i,t-1|≤U_Mi；

of formula (II) to (III)'_G,i,tThe output power P of the water-fire electric generator set of the preset receiving-end electric network of the ith receiving-end electric network at the moment t_Gmin,i,tThe minimum output power P of the water-fire electric generator set of the preset receiving-end electric network of the ith receiving-end electric network at the moment t_Gmax,i,tIs the maximum output power P 'of the hydro-thermal generator set of the ith receiving-end power grid at the moment t'_G,i,t-1Presetting the output power of a receiving-end power grid hydro-thermal generator set for the ith receiving-end power grid at the time of t-1, and U_MiThe maximum climbing rate of the ith receiving-end power grid hydro-thermal power generation unit is obtained.

In the technical scheme of the invention, the extra-high voltage direct current correction method for the transmitting-end power grid and the receiving-end power grid is used for establishing an optimization model by considering the requirements of the transmitting-end power grid and the receiving-end power grid, and the obtained correction result not only promotes the new energy consumption of the transmitting-end power grid, but also improves the peak regulation margin of the receiving-end power grid in the load valley period and relieves the peak regulation pressure of the receiving-end power grid. The economic cost of the two parties is considered, the optimal economy of the whole large system is taken as a target, and the feasibility and the practicability of the model are guaranteed. Prevent the receiving end electric wire netting from appearing "the anti-peak shaver" plan. The method can effectively improve the wind power and photovoltaic power generation consumption of the power grid at the sending end, reduce the wind and light abandoning rate, simultaneously ensure that the peak regulation margin of the power grid at the receiving end is increased at the load valley value, improve the peak regulation pressure of the power grid at the receiving end, ensure the stable operation of the power grid at the receiving end, and fully play an important role of the extra-high voltage line in fully implementing the national new energy development planning.

Drawings

Fig. 1 is a schematic flow chart of a first embodiment of an extra-high voltage dc correction method for a transmitting-end and receiving-end power grid according to the present invention.

Fig. 2 is a schematic diagram of a typical solar wind new energy consumption space of a transmission-end power grid in the invention.

Fig. 3 is a schematic diagram of a relationship between a typical daily grid load and a peak shaving margin.

Fig. 4 is a schematic diagram of typical daily peak regulation margin of a receiving-end power grid in the invention.

The objects, features and advantages of the present invention will be further explained with reference to the accompanying drawings.

Detailed Description

It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

In the following description, suffixes such as "module", "component", or "unit" used to denote elements are used only for facilitating the explanation of the present invention, and have no specific meaning in itself. Thus, "module", "component" or "unit" may be used mixedly.

Referring to fig. 1, to achieve the above object, the present invention provides an extra-high voltage dc correction method for a transmitting-end and receiving-end power grid, including the following steps:

step S100, establishing an extra-high voltage direct current correction model objective function considering a new energy consumption space of a transmitting-end power grid and a peak regulation margin of a receiving-end power grid;

step S200, establishing constraint conditions of the target function of the extra-high voltage direct current correction model, wherein the constraint conditions comprise power generation-load power balance constraint, peak regulation capacity balance constraint, preset extra-high voltage direct current tie line correction power constraint, extra-high voltage direct current tie line trading electric quantity constraint, end power grid load constraint and end power grid peak regulation margin correlation constraint, and end power grid hydro-thermal power generation unit peak regulation constraint;

step S300, calculating and determining a corrected extra-high voltage direct current tie line power curve according to the extra-high voltage direct current correction model objective function and the constraint condition;

and step S400, adjusting the extra-high voltage direct current tie line power according to the corrected extra-high voltage direct current tie line power curve.

In the technical scheme of the invention, the extra-high voltage direct current correction method considering the power grid at the transmitting end and the receiving end and the extra-high voltage direct current correction method considering the requirements of the transmitting end and the receiving end simultaneously establish a global optimization aiming at the whole power grid system at the transmitting end and the receiving end, consider that the direct current operation has the characteristic of adjustable transmission power within a constraint range, consider the randomness/intermittence of wind power and photovoltaic power generation and the load change of the power grid at the receiving end simultaneously, and prevent the power grid at the receiving end from generating a 'back peak regulation' plan on the basis of ensuring that the power grid at the transmitting end consumes the wind power and the photovoltaic power as much as possible. The wind power and photovoltaic power generation consumption of the power grid at the transmitting end can be effectively improved, the wind and light abandoning rate is reduced, the peak regulation margin of the power grid at the load valley value is increased, the peak regulation pressure of the power grid at the receiving end is improved, and the stable operation of the power grid at the receiving end is ensured.

Referring to fig. 4, in the receiving-end grid, for the receiving-end grid, the extra-high voltage dc link is used as a part of the power supply side to participate in power supply. If the power of the extra-high voltage direct current line tie line is corrected, the output power of the power generation side of the receiving-end power grid is necessarily changed, and the peak regulation margin of the receiving-end power grid is further influenced.

The peak-shaving margin comprises an upper peak-shaving margin and a lower peak-shaving margin, the load of the time interval minus the minimum output power (the minimum starting capacity of the water-gas-electric generator set plus the output power of the new energy (wind power, photovoltaic power)) of the power generation side of the time interval is the lower peak-shaving margin of the time interval, and the load of the time interval minus the maximum output power (the maximum starting capacity of the water-gas-electric generator set plus the output power of the new energy (wind power, photovoltaic power)) of the power generation side of the time interval is the upper peak-shaving margin of the time interval.

In the load low-valley period (the period that the peak regulation margin is insufficient easily occurs in the receiving-end power grid), if the power of the extra-high voltage direct current connecting line is reduced, the minimum output power of the power generation side of the receiving-end power grid is correspondingly reduced, the peak regulation margin of the receiving-end power grid is increased, and the peak regulation pressure is reduced; on the contrary, when the receiving-end power grid is in a load low-valley period of the receiving-end power grid, the power of the extra-high voltage direct-current connecting line is increased, the starting capacity of the hydroelectric generating set is reduced to the minimum, and in order to ensure that the peak regulation margin is larger than zero in the period, part of the hydroelectric generating set of the conventional power supply needs to be started, stopped and subjected to peak regulation, so that the peak regulation cost and the peak regulation difficulty of the receiving-end power grid are increased.

In the peak load period (the period when the peak reduction margin of the receiving-end power grid is sufficient), attention needs to be paid to the peak up-regulation margin of the receiving-end power grid, if the power of the extra-high voltage direct-current connecting line is increased in the period, the peak up-regulation margin of the system is increased, and the peak down-regulation margin is reduced, but the peak down-regulation margin of the receiving-end power grid at the period is sufficient, so that the safe operation of the system is not influenced, and the balance of the peak down-regulation margin at each period is ensured; if the power of the extra-high voltage direct current connecting line is reduced in the period, the peak-regulation margin on the system is reduced, and the increase of the peak-regulation margin can cause that the maximum output power of the power generation side of the receiving-end power grid is smaller than the load, so that the power supply is insufficient or the spare capacity of the system is insufficient in the peak period of the load, and certain hidden danger is caused to the safe and stable operation of the power grid.

Therefore, for a receiving-end power grid, the most ideal correction result of the extra-high voltage direct-current link is to reduce the power of the extra-high voltage direct-current line link in the load valley period; and increasing the power of the extra-high voltage direct current line tie line during the load peak period.

Referring to fig. 3, for the sending-end power grid, the extra-high voltage dc outgoing is considered to be transmitted to other areas only when the local area has excess new energy, so that the extra-high voltage dc link correction method provided by the present patent is set to not change the unit combination mode of the sending-end power grid, that is, the extra-high voltage dc link is corrected and the new energy consumption of the sending-end power grid is increased without changing the output power of the conventional power supply.

In the transmission-end power grid, the extra-high voltage direct-current tie line is equivalent to an extra added load. Therefore, for the sending-end power grid, the most ideal correction result of the extra-high voltage direct-current link power of the sending-end power grid is that the extra-high voltage direct-current line link power is increased in the load valley period of the sending-end power grid; and reducing the power of the extra-high voltage direct current line tie line during the load peak period.

For the power of the extra-high voltage direct current connecting line, the requirements of a transmitting end power grid and a receiving end power grid are contradictory, so that the requirements of the transmitting end power grid and the receiving end power grid need to be considered comprehensively, and a correction method is provided. Sending the end power grid with the aim of reducing the system operation cost, wherein the aim of reducing the wind and light abandoning cost is maximum; and the receiving-end power grid is used for constructing a correction model based on the change trend of the load of the receiving-end power grid and aiming at the minimum peak shaving cost of the power grid.

Establishing a corresponding function model, and finding out an optimal solution or a similar solution, for example, using an improved genetic algorithm or a YALMIP toolbox to call a CPLEX solver to solve, so as to obtain the optimal correction power of the extra-high voltage direct current tie line.

And obtaining preset correction power at different moments by solving the target function of the extra-high voltage direct current correction model and the constraint condition, drawing a corrected extra-high voltage direct current tie line power curve according to the solved optimal extra-high voltage direct current tie line correction power and the extra-high voltage direct current tie line power curve before correction, further adjusting a conventional unit power curve of a receiving-end power grid according to the optimal extra-high voltage direct current tie line correction power, and adjusting a new energy unit output power curve of a sending-end power grid according to the optimal extra-high voltage direct current tie line correction power.

Based on the first embodiment of the extra-high voltage dc correction method for the transmission-side and reception-side power grids, and the second embodiment of the extra-high voltage dc correction method for the transmission-side and reception-side power grids, the step S100 includes:

s110, acquiring preset extra-high voltage direct current tie line correction power, wind and light abandoning cost of a sending end power grid, extra-high voltage direct current tie line power before correction, sending end power grid load, receiving end power grid peak regulation cost, receiving end power grid load, new energy unit output power of a receiving end power grid and minimum output power of a receiving end power grid water-fire generator unit;

s120, determining the receiving-end power grid down-regulation peak margin according to the receiving-end power grid load, the output power of the receiving-end power grid new energy unit and the minimum output power of the receiving-end power grid hydro-thermal generator unit;

s130, determining a peak regulation margin of the receiving-end power grid according to the receiving-end power grid load, the output power of the new energy unit of the receiving-end power grid and the minimum output power of the hydro-thermal generator unit of the receiving-end power grid;

and S140, establishing the target function of the extra-high voltage direct current correction model according to the wind and light abandoning cost of the transmitting-end power grid, the added new energy consumption space, the peak regulation cost of the receiving-end power grid and the peak regulation margin of the receiving-end power grid.

Specifically, the new energy consumption space at different moments is determined by presetting the extra-high voltage direct current tie line power, the extra-high voltage direct current tie line power before correction and the load of a sending end power grid; and determining the peak regulation margin of the receiving-end power grid at different moments according to the load of the receiving-end power grid, the output power of the new energy unit of the receiving-end power grid and the minimum output power of the hydro-thermal generator unit of the receiving-end power grid, and calculating to obtain the reduced peak regulation capacity of the receiving-end power grid according to the corrected peak regulation margin and the peak regulation margin before correction.

Based on the second embodiment of the extra-high voltage direct current correction method considering the transmission-end and receiving-end power grids, in the third embodiment of the extra-high voltage direct current correction method considering the transmission-end and receiving-end power grids, the added new energy consumption space is determined by adopting the following calculation formula:

P_g,t＝P_LU,t-P_line,t；

P′_g,t＝P_LU,t-P_line,t-ΔP_line,t；

Q_t＝P′_g,t-P_g,t；

in the formula, Q_tNew energy consumption space, P, added for t moment of sending end power grid_g,tTo correct the original equivalent load, P ', of the frontend grid at time t'_g,tFor correcting the original equivalent load at time t of the back-end grid, P_LU,tFor the load of the transmitting grid at time t, P_line,tIs the power of the extra-high voltage DC tie line at the time t, delta P_line,tAnd presetting extra-high voltage direct-current connecting line correction power for the time t, namely the power of a new energy (wind power and photovoltaic power generation) unit which is consumed by a transmission end power grid in more.

Specifically, referring to fig. 2, for the sending-end power grid, under the condition that the load of the original sending-end power grid is not changed and the output power of the hydro-thermal power generator set of the sending-end power grid is not changed, the absorption space of the new energy source set (wind power and photovoltaic power) is increased, and the cost for wind abandoning and light abandoning of the sending-end power grid is reduced.

Based on the third embodiment of the extra-high voltage direct current correction method considering the transmitting end and receiving end power grids, in the fourth embodiment of the extra-high voltage direct current correction method considering the transmitting end and receiving end power grids, the peak regulation margin of the receiving end power grids is determined by adopting the following calculation formula:

P_YD,i,t＝P_LD,i,t-P_GU,min,i,t-P_NED,i,t-P_line,i,t；

in the formula, P_YD,i,tThe peak regulation margin P of the ith receiving end power grid at the moment t_GU,min,i,tThe minimum output power P of the ith receiving end power grid water-fire electric generator set at the moment t_LD,i,tLoad of receiving end power grid system at time t, P_NED,i,tThe minimum output power P of the wind power and photovoltaic generator set at the ith receiving end power grid at the moment t_line,i,tThe power of the high-voltage direct-current connecting line of the ith extra-high voltage direct-current connecting line at the moment t.

Specifically, the peak shaving problem is generally understood as whether the output power of the power supply can be reduced after the daily peak power balance condition is met to meet the load valley power balance requirement, so in the patent, the peak shaving margin of the receiving-end power grid is mainly controlled and calculated;

based on the fourth embodiment of the extra-high voltage direct current correction method considering the transmitting-end and receiving-end power grids, in the fifth embodiment of the extra-high voltage direct current correction method considering the transmitting-end and receiving-end power grids, an objective function of an extra-high voltage direct current correction model is as follows:

wherein,

P′_YD,i,t＝P_LD,i,t-P′_GU,min,i,t-P_NED,i,t-P_line,i,t-ΔP_line,i,t；

of formula (II) to (III)'_YD,i,tThe ith receiving grid is the peak regulation margin at the time t after correction, P'_GU,min,i,tThe minimum output power C of the hydro-thermal power generation unit at the moment t of the ith receiving-end power grid after preset correction₁Peak shaving cost for the receiving grid, C₂Light and wind abandoning cost for the sending-end power grid, M_tAnd F is the reduced peak shaving cost of the power grid system at the receiving end at the moment t.

Specifically, the purpose of correcting the power of the extra-high voltage direct-current connecting line is to reduce the wind and light abandoning cost to the maximum when a new energy consumption space is added to a transmitting-end power grid at the time t, and reduce the peak regulation cost to the maximum at the time t of a receiving-end power grid, so that the reduced operation cost of a transmitting-end power grid system is reduced to the maximum.

Based on any one of the first to fifth embodiments of the extra-high voltage direct current correction method for the transmission-side and receiving-side power grids, in the sixth embodiment of the extra-high voltage direct current correction method for the transmission-side and receiving-side power grids, the constraint of the correlation between the load of the receiving-side power grid and the peak regulation margin of the receiving-side power grid is as follows:

wherein,and the Pearson correlation coefficient represents the corrected load of the ith receiving-end power grid and the minimum output power of the generating side of the receiving-end power grid, and N is a preset value related to cost.

Specifically, the peak regulation margin of the receiving-end power grid is related to the load of the receiving-end power grid and the minimum output power of the receiving-end power grid power supply, the minimum output power of the receiving-end power grid power supply needs to be manually regulated and controlled according to the load of the receiving-end power grid, and the relation between the minimum output power of the receiving-end power grid power supply and the load of the receiving-end power grid can be expressed by a Pearson correlation coefficient, namely the peak regulation margin of the receiving-end power grid is increased in a load valley period, and the situation that the peak regulation space is insufficient in a valley period is relieved; when the load is high, the peak regulation margin of the receiving-end power grid is sufficient, a part of the peak regulation margin can be properly reduced, the preset value of the correlation coefficient is adjusted as required, the peak regulation cost is higher as the correlation is higher, in the field of natural science, the pearson correlation coefficient is widely used for measuring the correlation degree between two variables, and the value of the pearson correlation coefficient is between-1 and 1), and the expression of the pearson correlation coefficient is as follows:

and describing a practical scheduling decision process by taking a typical day of a certain province as an example, so as to calculate and obtain the minimum output power of the water-gas-electric generator set of the power grid system. The method comprises the following specific steps:

1) in order to ensure that the system still has enough power supply output power at the maximum load value, the maximum load of a typical day plus the load reserve and the accident rotation reserve are taken as the adjustable capacity requirements of the system for all power supplies in the peak period; then, the effective capacity of the new energy source unit (wind power and photovoltaic power) in the peak time period is subtracted (the wind power and the photovoltaic power are taken as power sources instead of negative loads, and the essence of the wind power and the photovoltaic power is the same as the equivalent load curve considering the wind power standby decision at the same time) to serve as the adjustable capacity requirement of the system for the conventional power source in the peak time period on the day.

2) According to the adjustable capacity requirement, the power supply capacities of the tie lines, hydroelectric power, nuclear power, fuel gas and the like are preferably balanced in a unit power generation scheduling sequence specified in an energy-saving power generation scheduling method (trial implementation), wherein if the province is a receiving end, the tie lines in the outer region can be equivalently regarded as a power supply, if the province is a sending section, the tie lines in the outer region are equivalently regarded as a part of a load, and finally the residual capacity requirement (the peak adjustable capacity requirement minus the adjustable capacity of the various priority units) is the starting capacity of the thermal power unit.

3) Determining the minimum starting capacity of the thermal power unit according to the starting capacity of the thermal power unit and the corresponding peak shaving depth

4) Adding the minimum starting capacity of all the conventional power supplies to obtain the minimum output power of the conventional power supplies (the minimum output power of the conventional power supplies is the minimum output power of the power generation side plus the minimum output power of wind power and photovoltaic power generation)

Based on any one of the first to fifth embodiments of the extra-high voltage direct current correction method for the transmission-side and receiving-side power grids, in a seventh embodiment of the extra-high voltage direct current correction method for the transmission-side and receiving-side power grids, the extra-high voltage direct current tie line power constraint includes an extra-high voltage direct current tie line power regulation rate constraint and an extra-high voltage direct current tie line power regulation range constraint;

wherein, the power regulation rate constraint of the extra-high voltage direct current tie line is as follows:

|(P_line,i,t+ΔP_line,i,t)-(P_line,i,t-1+ΔP_line,i,t-1)|≤U_Zi；

in the formula of U_ZiFor the maximum regulation rate, P, of the ith extra-high voltage DC tie line power_line,i,tThe power, delta P, of the ith extra-high voltage DC link at time t_line,i,tCorrecting power for preset extra-high voltage direct current tie line of ith extra-high voltage direct current tie line at time t, P_line,i,t-1The ultra-high voltage direct current tie line power, delta P, of the ith ultra-high voltage direct current tie line at the time t-1_line,i,t-1Correcting power for a preset extra-high voltage direct current tie line of the ith extra-high voltage direct current tie line at the time of t-1;

the extra-high voltage direct current tie line power regulation range constraint is as follows:

P_Simin≤P_line,i,t+ΔP_line,i,t≤P_Simax；

in the formula, P_SimaxThe power safety upper limit, P, of the ith extra-high voltage direct current tie line_SiminAnd the power safety lower limit of the extra-high voltage direct current tie line of the ith extra-high voltage direct current tie line is set.

Specifically, the extra-high voltage direct current tie line in the actual operation process, if need be to extra-high voltage direct current tie line power regulation, for extra-high voltage direct current tie line's safety and life, the regulation rate of ith extra-high voltage direct current tie line power need be less than ith extra-high voltage direct current tie line power's maximum regulation rate after the correction, extra-high voltage direct current tie line has its safe upper limit and safe lower limit simultaneously, therefore ith extra-high voltage direct current tie line power size need be in extra-high voltage direct current tie line's safe power.

Based on any one of the first to fifth embodiments of the extra-high voltage direct current correction method for the transmission-side and receiving-side power grids, in an eighth embodiment of the extra-high voltage direct current correction method for the transmission-side and receiving-side power grids, the power generation-load power balance constraint includes: the method comprises the following steps of carrying out power generation-load power balance constraint on a transmitting-end power grid and carrying out power generation-load power balance constraint on a receiving-end power grid;

wherein, the power generation-load power balance constraint of the sending end power grid is as follows:

P_G,t+P'_NE,t＝P_L,t+P_line,t+ΔP_line,t；

in the formula, P_line,tIs the power of the extra-high voltage DC tie line at the time t, delta P_line,tPresetting extra-high voltage DC tie line correction power P for time t_G,tThe power of a water-fire-electricity generator set of a sending end power grid at the moment of tRate, P'_NE,tPresetting the power P of the wind power and the photovoltaic generator set for a transmitting end power grid at the moment t_L,tSending end power grid load at time t;

the power generation-load power balance constraint of the receiving-end power grid is as follows:

P'_G,i,t+P_NE,i,t+P_line,i,t+ΔP_line,i,t＝P_L,i,t；

of formula (II) to (III)'_G,i,tThe power P of a preset receiving-end power grid hydro-thermal generator set of the ith receiving-end power grid at the moment t_L,i,tReceiving end power grid load P of ith receiving end power grid at time t_NE,i,tThe power P of the wind power generation unit and the photovoltaic generator set of the ith receiving end power grid at the moment t_line,i,tThe power, delta P, of the ith extra-high voltage DC link at time t_line,i,tAnd correcting the power of the preset extra-high voltage direct current tie line of the ith extra-high voltage direct current tie line at the time t.

Specifically, since power generation and power consumption are completed in the same time, the generated power is not necessarily exactly equal to the power consumption. The active load and the reactive load of the power system are changed frequently, so that the balance is broken frequently, and the effort is made to achieve the balance, so that the power balance is dynamic, the temporary balance is obtained in the unbalance, and the method is an important measure for alleviating the power supply and demand contradiction to a certain extent.

Based on any one of the first to fifth embodiments of the extra-high voltage direct current correction method for the transmission-side and receiving-side power grids, in the ninth embodiment of the extra-high voltage direct current correction method for the transmission-side and receiving-side power grids, the peak regulation capacity balance constraint comprises a transmission-side power grid peak regulation capacity balance constraint and a transmission-side power grid peak regulation capacity balance constraint;

the peak regulation capacity balance constraint of the power grid at the sending end is as follows:

H_U> 0 and L_UThe conditions are satisfied at the same time when the pressure is greater than 0,

wherein,

H_U＝P_GUmax-P_lineHU-ΔP_lineHU-P'_LUmax-P_RHU；

L_U＝P'_LUmin+P_lineLU+ΔP_lineLU-P_GminU-P_RLU；

in the formula, H_uThe peak regulation margin L on the transmission end power grid at the peak load period of the transmission end power grid_UFor the sending end power grid down-regulation peak margin, P, in the low peak period of the sending end power grid load_GUmaxThe maximum output power, P, can be adjusted for the water-fire electric generator set of the sending end power grid in the peak load period of the sending end power grid_lineHUFor the power, delta P, of the extra-high voltage direct-current tie line during the peak load period of the transmission-end power grid_lineHUPresetting correction power P 'of extra-high voltage direct current tie line for transmission-end power grid in load peak period of transmission-end power grid'_LUmaxThe maximum equivalent load P is the typical daily load of the sending end power grid minus the new energy output power of the sending end power grid_RHUReserve capacity, P ', for a sending-side grid during peak load periods of the sending-side grid'_LUminThe minimum output power, P, can be adjusted for the water-fire electric generator set of the power grid at the load bottom peak period of the power grid at the sending end_lineLUIs the ultra-high voltage direct current tie line power, delta P, of the power grid at the load bottom peak period of the power grid at the sending end_lineLUPresetting extra-high voltage direct current tie line correction power for transmission end power grid in load bottom peak period of transmission end power grid_GminUThe minimum equivalent load P of the typical daily load of the sending-end power grid minus the new energy output power of the sending-end power grid_RLUThe reserve capacity is the reserve capacity in the load low peak period of the power grid at the sending end;

the peak regulation capacity balance constraint of the sending end power grid is as follows:

H_D> 0 and L_DThe conditions are satisfied at the same time when the pressure is greater than 0,

wherein,

H_D＝P_GDmax+P_lineHD+ΔP_lineHD-P'_LDmax-P_RHD；

L_D＝P'_LDmin-P_GDmin-P_lineLD-ΔP_lineLD-P_RLD；

in the formula, H_DFor the receiving-end grid being in peak load period of the receiving-end gridUp peak margin, P_GDmaxThe minimum output power, P, can be adjusted for the receiving-end power grid hydro-thermal generator set in the load bottom peak period of the receiving-end power grid_lineHDIs the extra-high voltage direct current tie line power, delta P, of the receiving-end power grid in the load bottom peak period of the receiving-end power grid_lineHDPresetting correction power P 'of extra-high voltage direct current tie line for receiving-end power grid in load bottom peak period of receiving-end power grid'_LDmaxThe minimum equivalent load, P, of the typical daily load of the receiving-end power grid minus the wind power photovoltaic output power of the receiving-end power grid_RHDReserve capacity, L, for the receiving end grid during low peak periods of receiving end grid load_DFor the receiving end power grid under-regulation peak margin in the receiving end power grid load peak period, P_GDminThe minimum output power, P, of the receiving-end power grid hydro-thermal generator set in the load bottom peak period of the receiving-end power grid can be adjusted_lineLDIs the extra-high voltage direct current tie line power, delta P, of the receiving end power grid in the load bottom peak period of the receiving end power grid_lineLDPresetting correction power P 'of extra-high voltage direct current tie line for receiving-end power grid in load bottom peak period of receiving-end power grid'_LDminThe minimum equivalent load, P, of the typical daily load of the receiving-end power grid minus the wind power photovoltaic output power of the receiving-end power grid_RLDAnd the standby capacity of the receiving end power grid in the low peak load period of the receiving end power grid is obtained.

Specifically, in the adjusting process, the upper adjusting margin of the power grid system at the peak time of the power grid load needs to be greater than zero, that is, the maximum adjustable output power is greater than the maximum load of the power grid system, otherwise, the power generation amount is smaller than the power grid load, and the lower adjusting margin of the power grid system needs to be greater than zero, that is, the minimum adjustable output power is greater than the minimum load of the power grid system, otherwise, the power generation amount is greater than the power grid load, please refer to fig. 3, if the lower adjusting margin is greater than 0, it indicates that the peak space of the system is sufficient, if the lower adjusting margin is less than 0, it indicates that the peak space of the system is insufficient at the moment, it needs to abandon the wind, abandon the light or reduce the output power of the hydroelectric generating set, and in areas with rich wind power and photovoltaic power generation, a wind abandon light abandon measure is generally adopted to ensure the normal, if the peak regulation margin is less than 0, the power supply is insufficient or the system standby capacity is insufficient in the peak load period, so that certain hidden danger is brought to the safe and stable operation of the power grid.

Based on any one of the first to fifth embodiments of the extra-high voltage direct current correction method for the transmission-side and receiving-side power grids, in the tenth embodiment of the extra-high voltage direct current correction method for the transmission-side and receiving-side power grids, the establishment of the constraint of the preset extra-high voltage direct current tie line correction power, the constraint of the extra-high voltage direct current tie line transaction electric quantity and the peak regulation constraint of the receiving-side power grid hydroelectric generating set are as follows:

wherein, the preset extra-high voltage direct current tie line modified power constraint is as follows:

-P_line,t≤ΔP_line,t≤P_NEU,max,t-P_line,t；

in the formula,. DELTA.P_line,tCorrecting the power for the preset extra-high voltage DC link at time t, P_line,tFor extra-high voltage DC link power at time t, P_NEU,max,tThe maximum possible output power of the wind-solar unit of the power grid at the sending end is obtained;

the extra-high voltage direct current connecting line transaction electric quantity constraint is as follows:

in the formula, E_Z,i,maxFor the maximum transaction electric quantity of the ith extra-high voltage direct current connecting line in a planning period T, E_Z,_i,minFor the minimum transaction electric quantity of the ith extra-high voltage direct current connecting line in the planning period T,

for the transaction electric quantity of the ith extra-high voltage direct current connecting line in the planning period T, P_line,i,tThe power, delta P, of the ith extra-high voltage DC link at time t_line,i,tCorrecting power for a preset extra-high voltage direct current tie line of the ith extra-high voltage direct current tie line at the time t;

the power constraint of the receiving-end power grid water-fire electric generator set is as follows:

P_Gmin,i,t≤P'_G,i,t≤P_Gmax,i,t；

|P'_G,i,t-P'_G,i,t-1|≤U_Mi；

of formula (II) to (III)'_G,i,tThe output power P of the water-fire electric generator set of the preset receiving-end electric network of the ith receiving-end electric network at the moment t_Gmin,i,tThe minimum output power P of the water-fire electric generator set of the preset receiving-end electric network of the ith receiving-end electric network at the moment t_Gmax,i,tIs the maximum output power P 'of the hydro-thermal generator set of the ith receiving-end power grid at the moment t'_G,i,t-1Presetting the output power of a receiving-end power grid hydro-thermal generator set for the ith receiving-end power grid at the time of t-1, and U_MiThe maximum climbing rate of the ith receiving-end power grid hydro-thermal power generation unit is obtained.

Specifically, the upper limit of the correction power of the extra-high voltage direct-current connecting line is the difference between the maximum possible output power of the wind and light unit of the power grid at the sending end and the correction power of the extra-high voltage direct-current connecting line before correction, the lower limit of the correction power of the extra-high voltage direct-current connecting line is negative correction power of the extra-high voltage direct-current connecting line before correction, and the correction power of the extra-high voltage direct-current connecting line can only correct the corrected extra-high voltage direct-current connecting line power to the maximum possible output power of the wind and light unit of the power grid at the sending end at the maximum value or correct the corrected extra-high voltage direct-current connecting.

The transmission price and the transmission quantity of the transmission between different power grids are planned and regulated by related departments, so that the transmitted electric quantity, namely the transaction electric quantity of the extra-high voltage direct current connecting line in a certain planning period is limited.

In the operation process of the water-fire electric machine set, the output power of the water-fire electric machine set comprises the maximum output power and the minimum output power, the output power of the corrected transmission end electric network water-fire electric machine set cannot be larger than the maximum output power of the water-fire electric machine set and cannot be smaller than the minimum output power of the water-fire electric machine set, and meanwhile, when the water-fire electric machine set is used for adjusting generated energy, the water flow or fire needs to be changed firstly, so that certain reaction time exists during adjustment, and meanwhile, the adjusting speed of the water-fire electric machine set is limited to prevent the water-fire electric machine set from being damaged, the service life is prolonged, and therefore, the change power of the corrected extra-high voltage direct current connecting line power cannot be larger than the maximum climbing rate of the water-.

In the description herein, references to the description of the term "one embodiment," "another embodiment," or "first through xth embodiments," etc., mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials, method steps, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

It should be noted that, in this document, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or system that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or system. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other like elements in a process, method, article, or system that comprises the element.

The above-mentioned serial numbers of the embodiments of the present invention are merely for description and do not represent the merits of the embodiments.

The above description is only a preferred embodiment of the present invention, and not intended to limit the scope of the present invention, and all modifications of equivalent structures and equivalent processes, which are made by using the contents of the present specification and the accompanying drawings, or directly or indirectly applied to other related technical fields, are included in the scope of the present invention.

Claims (10)

1. An extra-high voltage direct current correction method considering a transmitting end power grid and a receiving end power grid is characterized by comprising the following steps:

establishing an extra-high voltage direct current correction model objective function considering a new energy consumption space of a transmitting-end power grid and a peak regulation margin of a receiving-end power grid;

establishing constraint conditions of the target function of the extra-high voltage direct current correction model, wherein the constraint conditions comprise power generation-load power balance constraint, peak regulation capacity balance constraint, preset extra-high voltage direct current tie line correction power constraint, extra-high voltage direct current tie line transaction electric quantity constraint, end power grid load constraint and end power grid peak regulation margin correlation constraint, and end power grid water-heat power generation unit peak regulation constraint;

calculating and determining a corrected extra-high voltage direct current tie line power curve according to the extra-high voltage direct current correction model objective function and the constraint condition;

and adjusting the power of the extra-high voltage direct current tie line according to the corrected power curve of the extra-high voltage direct current tie line.

2. The extra-high voltage direct current correction method considering the transmitting-end and receiving-end power grids according to claim 1, wherein the step of establishing an extra-high voltage direct current correction model objective function considering a new energy consumption space of the transmitting-end power grid and a peak regulation margin of the receiving-end power grid comprises the steps of:

acquiring preset correction power of the extra-high voltage direct-current connecting line, wind and light abandoning cost of a sending-end power grid, extra-high voltage direct-current connecting line power before correction, sending-end power grid load, peak shaving cost of a receiving-end power grid, receiving-end power grid load, output power of a new energy source unit of the receiving-end power grid and minimum output power of a water-fire motor unit of the receiving-end power grid;

determining an increased new energy consumption space according to the preset extra-high voltage direct current tie line correction power, the extra-high voltage direct current tie line power before correction and the sending end power grid load;

determining the peak reduction margin of the receiving-end power grid according to the receiving-end power grid load, the output power of the new energy unit of the receiving-end power grid and the minimum output power of the hydro-thermal generator unit of the receiving-end power grid;

and establishing the target function of the extra-high voltage direct current correction model according to the wind and light abandoning cost of the transmitting-end power grid, the added new energy consumption space, the peak regulation cost of the receiving-end power grid and the peak regulation margin of the receiving-end power grid.

3. The extra-high voltage direct current correction method considering the transmitting-end and receiving-end power grids according to claim 2, wherein the added new energy consumption space is determined by adopting the following calculation formula:

P_g,t＝P_LU,t-P_line,t；

P′_g,t＝P_LU,t-P_line,t-ΔP_line,t；

Q_t＝P'_g,t-P_g,t；

in the formula, Q_tNew energy consumption space, P, added for t moment of sending end power grid_g,tTo correct the original equivalent load, P ', of the frontend grid at time t'_g,tFor correcting the original equivalent load at time t of the back-end grid, P_LU,tFor the load of the transmitting grid at time t, P_line,tIs the power of the extra-high voltage DC tie line at the time t, delta P_line,tAnd presetting the correction power of the extra-high voltage direct current tie line at the time t.

4. The method of claim 3, wherein the calculation of the peak shaving margin of the receiving-end power grid adopts the following calculation formula:

P_YD,i,t＝P_LD,i,t-P_GU,min,i,t-P_NED,i,t-P_line,i,t；

in the formula, P_YD,i,tThe peak regulation margin P of the ith receiving end power grid at the moment t_GU,min,i,tThe minimum output power P of the ith receiving end power grid water-fire electric generator set at the moment t_LD,i,tLoad of receiving end power grid system at time t, P_NED,i,tThe minimum output power P of the wind power and photovoltaic generator set at the ith receiving end power grid at the moment t_line,i,tThe power of the ith extra-high voltage direct current tie line at the time t.

5. The extra-high voltage direct current correction method considering the transmitting end and receiving end power grids according to claim 4, wherein the extra-high voltage direct current correction model objective function is as follows:

wherein,

P′_YD,i,t＝P_LD,i,t-P′_GU,min,i,t-P_NED,i,t-P_line,i,t-ΔP_line,i,t；

of formula (II) to (III)'_YD,i,tThe ith receiving grid is the peak regulation margin at the time t after correction, P'_GU,min,i,tThe minimum output power C of the hydro-thermal power generation unit at the moment t of the ith receiving-end power grid after preset correction₁Peak shaving cost for the receiving grid, C₂Light and wind abandoning cost for the sending-end power grid, M_tAnd F is the reduced peak shaving cost of the power grid system at the receiving end at the moment t.

6. The extra-high voltage direct current correction method considering the sending-end and receiving-end power grids according to any one of claims 1 to 5, wherein the constraint of the correlation between the load of the receiving-end power grid and the peak shaving margin of the receiving-end power grid is as follows:

wherein,

and the Pearson correlation coefficient represents the corrected load of the receiving end power grid of the ith receiving end power grid and the minimum output power of the power supply of the receiving end power grid, and N is a preset value related to cost.

7. The extra-high voltage direct current correction method considering the sending-end and receiving-end power grids according to any one of claims 1 to 5, wherein the constraints on the extra-high voltage direct current tie line power comprise an extra-high voltage direct current tie line power regulation rate constraint and an extra-high voltage direct current tie line power regulation range constraint;

wherein, the power regulation rate constraint of the extra-high voltage direct current tie line is as follows:

|(P_line,i,t+ΔP_line,i,t)-(P_line,i,t-1+ΔP_line,i,t-1)|≤U_Zi；

in the formula of U_ZiFor the maximum regulation rate, P, of the ith extra-high voltage DC tie line power_line,i,tThe power, delta P, of the ith extra-high voltage DC link at time t_line,i,tCorrecting power for preset extra-high voltage direct current tie line of ith extra-high voltage direct current tie line at time t, P_line,i,t-1The ultra-high voltage direct current tie line power, delta P, of the ith ultra-high voltage direct current tie line at the time t-1_line,i,t-1Correcting power for a preset extra-high voltage direct current tie line of the ith extra-high voltage direct current tie line at the time of t-1;

the extra-high voltage direct current tie line power regulation range constraint is as follows:

P_Simin≤P_line,i,t+ΔP_line,i,t≤P_Simax；

in the formula, P_SimaxThe power safety upper limit, P, of the ith extra-high voltage direct current tie line_SiminAnd the power safety lower limit of the extra-high voltage direct current tie line of the ith extra-high voltage direct current tie line is set.

8. The extra-high voltage direct current modification method considering the sending-end and receiving-end power grids according to any one of claims 1 to 5, wherein the power generation-load power balance constraint comprises: the method comprises the following steps of carrying out power generation-load power balance constraint on a transmitting-end power grid and carrying out power generation-load power balance constraint on a receiving-end power grid;

wherein, the power generation-load power balance constraint of the sending end power grid is as follows:

P_G,t+P'_NE,t＝P_L,t+P_line,t+ΔP_line,t；

in the formula, P_line,tIs the power of the extra-high voltage DC tie line at the time t, delta P_line,tPresetting extra-high voltage DC tie line correction power P for time t_G,tIs the power of a hydro-thermal generator set of a transmission end grid at time t'_NE,tPresetting the power P of the wind power and the photovoltaic generator set for a transmitting end power grid at the moment t_L,tSending end power grid load at time t;

the power generation-load power balance constraint of the receiving-end power grid is as follows:

P'_G,i,t+P_NE,i,t+P_line,i,t+ΔP_line,i,t＝P_L,i,t；

of formula (II) to (III)'_G,i,tThe power P of a preset receiving-end power grid hydro-thermal generator set of the ith receiving-end power grid at the moment t_L,i,tReceiving end power grid load P of ith receiving end power grid at time t_NE,i,tThe power P of the wind power generation unit and the photovoltaic generator set of the ith receiving end power grid at the moment t_line,i,tThe power, delta P, of the ith extra-high voltage DC link at time t_line,i,tAnd correcting the power of the preset extra-high voltage direct current tie line of the ith extra-high voltage direct current tie line at the time t.

9. The extra-high voltage direct current modification method considering the sending-end and receiving-end power grids according to any one of claims 1 to 5, wherein the constraint on the peak shaving capacity balance comprises: peak regulation capacity balance constraint of a sending end power grid and peak regulation capacity balance constraint of the sending end power grid;

the peak regulation capacity balance constraint of the power grid at the sending end is as follows:

H_U> 0 and L_UThe conditions are satisfied at the same time when the pressure is greater than 0,

wherein,

H_U＝P_GUmax-P_lineHU-ΔP_lineHU-P'_LUmax-P_RHU；

L_U＝P'_LUmin+P_lineLU+ΔP_lineLU-P_GminU-P_RLU；

in the formula, H_uThe peak regulation margin L on the transmission end power grid at the peak load period of the transmission end power grid_UFor the sending end power grid down-regulation peak margin, P, in the low peak period of the sending end power grid load_GUmaxThe maximum output power, P, can be adjusted for the water-fire electric generator set of the sending end power grid in the peak load period of the sending end power grid_lineHUFor the power, delta P, of the extra-high voltage direct-current tie line during the peak load period of the transmission-end power grid_lineHUPresetting correction power P 'of extra-high voltage direct current tie line for transmission-end power grid in load peak period of transmission-end power grid'_LUmaxThe maximum equivalent load P is the typical daily load of the sending end power grid minus the new energy output power of the sending end power grid_RHUReserve capacity, P ', for a sending-side grid during peak load periods of the sending-side grid'_LUminThe minimum output power, P, can be adjusted for the water-fire electric generator set of the power grid at the load bottom peak period of the power grid at the sending end_lineLUIs the ultra-high voltage direct current tie line power, delta P, of the power grid at the load bottom peak period of the power grid at the sending end_lineLUPresetting extra-high voltage direct current tie line correction power for transmission end power grid in load bottom peak period of transmission end power grid_GminUThe minimum equivalent load P of the typical daily load of the sending-end power grid minus the new energy output power of the sending-end power grid_RLUThe reserve capacity is the reserve capacity in the load low peak period of the power grid at the sending end;

the peak regulation capacity balance constraint of the sending end power grid is as follows:

H_D> 0 and L_DThe conditions are satisfied at the same time when the pressure is greater than 0,

wherein,

H_D＝P_GDmax+P_lineHD+ΔP_lineHD-P'_LDmax-P_RHD；

L_D＝P'_LDmin-P_GDmin-P_lineLD-ΔP_lineLD-P_RLD；

in the formula, H_DThe peak up-regulation margin P of the receiving-end power grid in the peak load period of the receiving-end power grid_GDmaxThe minimum output power, P, can be adjusted for the receiving-end power grid hydro-thermal generator set in the load bottom peak period of the receiving-end power grid_lineHDTo be at receiving end of power gridUltra-high voltage direct current tie line power, delta P, of receiving-end power grid in load bottom peak period_lineHDPresetting correction power P 'of extra-high voltage direct current tie line for receiving-end power grid in load bottom peak period of receiving-end power grid'_LDmaxThe minimum equivalent load, P, of the typical daily load of the receiving-end power grid minus the wind power photovoltaic output power of the receiving-end power grid_RHDReserve capacity, L, for the receiving end grid during low peak periods of receiving end grid load_DFor the receiving end power grid under-regulation peak margin in the receiving end power grid load peak period, P_GDminThe minimum output power, P, of the receiving-end power grid hydro-thermal generator set in the load bottom peak period of the receiving-end power grid can be adjusted_lineLDIs the extra-high voltage direct current tie line power, delta P, of the receiving end power grid in the load bottom peak period of the receiving end power grid_lineLDPresetting correction power P 'of extra-high voltage direct current tie line for receiving-end power grid in load bottom peak period of receiving-end power grid'_LDminThe minimum equivalent load, P, of the typical daily load of the receiving-end power grid minus the wind power photovoltaic output power of the receiving-end power grid_RLDAnd the standby capacity of the receiving end power grid in the low peak load period of the receiving end power grid is obtained.

10. The extra-high voltage direct current correction method considering the sending end and the receiving end power grids according to any one of claims 1 to 5, wherein the establishment of the constraint of the preset extra-high voltage direct current tie line correction power, the constraint of the extra-high voltage direct current tie line trade electricity quantity and the peak regulation constraint of the receiving end power grid hydro-thermal power generating unit is as follows:

wherein, the preset extra-high voltage direct current tie line modified power constraint is as follows:

-P_line,t≤ΔP_line,t≤P_NEU,max,t-P_line,t；

in the formula,. DELTA.P_line,tCorrecting the power for the preset extra-high voltage DC link at time t, P_line,tFor extra-high voltage DC link power at time t, P_NEU,max,tThe maximum possible output power of the wind-solar unit of the power grid at the sending end is obtained;

the extra-high voltage direct current connecting line transaction electric quantity constraint is as follows:

in the formula, E_Z,i,maxFor the maximum transaction electric quantity of the ith extra-high voltage direct current connecting line in a planning period T, E_Z,i,minFor the minimum transaction electric quantity of the ith extra-high voltage direct current connecting line in the planning period T,

for the transaction electric quantity of the ith extra-high voltage direct current connecting line in the planning period T, P_line,i,tThe power, delta P, of the ith extra-high voltage DC link at time t_line,i,tCorrecting power for a preset extra-high voltage direct current tie line of the ith extra-high voltage direct current tie line at the time t;

the power constraint of the receiving-end power grid water-fire electric generator set is as follows:

P_Gmin,i,t≤P'_G,i,t≤P_Gmax,i,t；

|P'_G,i,t-P'_G,i,t-1|≤U_Mi；

of formula (II) to (III)'_G,i,tThe output power P of the water-fire electric generator set of the preset receiving-end electric network of the ith receiving-end electric network at the moment t_Gmin,i,tThe minimum output power P of the water-fire electric generator set of the preset receiving-end electric network of the ith receiving-end electric network at the moment t_Gmax,i,tIs the maximum output power P 'of the hydro-thermal generator set of the ith receiving-end power grid at the moment t'_G,i,t-1Presetting the output power of a receiving-end power grid hydro-thermal generator set for the ith receiving-end power grid at the time of t-1, and U_MiThe maximum climbing rate of the ith receiving-end power grid hydro-thermal power generation unit is obtained.

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