A computing process and speed-up method considering remote collaborative adjustment of multiple power electronic devices

Abstract

This invention discloses a calculation process and speed-up method for remote coordinated adjustment of various power electronic devices, including the following steps: 1) acquiring input power system data and establishing physical models of various power electronic devices; 2) calculating a modular local sensitivity matrix based on the physical models of the power electronic devices; 3) calculating the target physical quantity y; 4) obtaining the minimum change Δu of the control parameters of the power electronic devices during the k-th alternating iteration through pseudo-inverse calculation based on the modular local sensitivity matrix and the target physical quantity y. (k) and update the control parameter u (k+1) =u (k) +Δu (k) 4) Determine whether the active power of the tie line and the alternating iterative power flow both satisfy the convergence criterion at the k-th iteration. If so, output the control parameters of the power electronic equipment; otherwise, return to step 2). This invention can reuse the calculation results of the alternating iterative method and directly obtain the local sensitivity calculation, thus improving the solution efficiency of the remote coordinated adjustment strategy.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of power electronic device adjustment, and particularly relates to a calculation process and speed-up method considering remote cooperative adjustment of multiple power electronic devices. BACKGROUND

[0002] With the continuous expansion of the scale of the power system, the technical challenges brought by the increasing renewable energy grid capacity and the growing number of power electronic devices (PEDs) deployed have become a research hotspot. Large-scale renewable energy access leads to significant random characteristics of the power system, which greatly increases the probability of key area faults and thus causes cascading power outages. Rapid advances in material science and control technology have driven the widespread application of power electronic devices in power systems. The application of power electronic devices in power systems mainly focuses on high-voltage direct current (HVDC) and flexible alternating current transmission systems (FACTS). Voltage source converters (VSCs) as the core equipment of high-voltage direct current, can independently adjust active and reactive power, and realize the adjustment of current direction while maintaining the polarity of voltage. In recent years, research on AC / DC hybrid systems based on VSC-HVDC has continued to increase. Flexible alternating current transmission systems include unified power flow controllers (UPFC), generalized unified power flow controllers (GUPFC), static synchronous compensators (STATCOM), static synchronous series compensators (SSSC), and other devices, which have comprehensive functions such as voltage regulation, series compensation, power control, and phase adjustment. These devices achieve fine-tuned regulation and dynamic optimization of electrical parameters, opening up new paths for ensuring the safe and stable operation of modern power systems.

[0003] Generally, the adjustment of power electronic devices mainly focuses on the adjustment of physical quantities at their locations, i.e. local adjustment. However, depending on local adjustment alone may lead to the physical quantities in the areas without installed devices failing to meet the requirements or even exceeding the limit, especially for large-scale installation of power electronic devices. Therefore, it is particularly important to study the coordinated adjustment strategy of power electronic devices, which not only needs to consider the comprehensive influence of each power electronic device on the controlled physical quantity, but also needs to consider the overall adjustment, so as to improve the ability of power electronic devices to respond to system requirements under different operating conditions (including load change, new energy grid connection, system fault, etc.), and to enhance the flexibility and safety of the entire power system operation.

[0004] Generally, the adjustment of power electronic devices mainly focuses on the adjustment of physical quantities at their locations, i.e. local adjustment. However, depending on local adjustment alone may lead to the physical quantities in the areas without installed devices failing to meet the requirements or even exceeding the limit, especially for large-scale installation of power electronic devices. Therefore, it is particularly important to study the coordinated adjustment strategy of power electronic devices, which not only needs to consider the comprehensive influence of each power electronic device on the controlled physical quantity, but also needs to consider the overall adjustment, so as to improve the ability of power electronic devices to respond to system requirements under different operating conditions (including load change, new energy grid connection, system fault, etc.), and to enhance the flexibility and safety of the entire power system operation.

[0005] However, the traditional optimization method is time-consuming in solving process, and the processing of the optimization model to improve the solving efficiency may not be transparent enough in controlling the accuracy of the solving result, and lacks credibility. SUMMARY

[0006] The purpose of the present application is to provide a calculation process and speed-up method considering the coordinated adjustment of multiple power electronic devices at a remote end, comprising the following steps:

[0007] 1) Obtain input power system data and establish physical models of various power electronic devices;

[0008] 2) Calculate the modular local sensitivity matrix based on the physical models of the power electronic devices;

[0009] 3) Calculate the target physical quantity y;

[0010] 4) Based on the modular local sensitivity matrix and the target physical quantity y, the minimum change amount of the power electronic device control parameter at the kth alternating iteration is obtained through pseudo-inverse calculation (k) , and the control parameter u (k+1) is updated as u (k) +Δu (k) ;

[0011] 4) judging whether the active power of the tie line and the alternating iteration power flow satisfy the convergence criterion at the kth iteration, if yes, outputting the control parameter of the power electronic device, otherwise returning to step 2).

[0012] Further, the basic data of the power system includes the topology of the power system, the source and load size and position, the type and quantity of the power electronic device.

[0013] Further, the physical model of each type of power electronic device includes a power electronic device steady-state model, an alternating current system model and a direct current system model.

[0014] The power electronic device steady-state model includes the unbalanced equation of the VSC converter station, GUPFC, STATCOM and SSSC.

[0015] Further, the unbalanced equation of the VSC converter station is as follows:

[0016]

[0017] In the formula, P c.dc is the active power flowing from the converter station to the direct current system; ΔP c.dc is the active power imbalance of the converter station flowing to the direct current system; P loss is the active power loss; P c is the active power of node c; ΔP f , ΔQ f is the active power and reactive power imbalance of node f; P cf , Q cf is the active power and reactive power of node f flowing to node c; P fp , Q fp is the active power and reactive power of node f flowing to node p; Q f is the reactive power output by node f; Q p is the reactive power flowing from the converter station to node p; is the reactive power reference value; ΔQ p is the reactive power imbalance flowing to node p;

[0018] The unbalanced equation of GUPFC is as follows:

[0019]

[0020] In the formula, V p is the voltage amplitude of node p; is the reference voltage amplitude of node p; ΔV p is the voltage amplitude imbalance of node p; Q sh is the reactive power flowing from node p to the parallel side of GUPFC; Q is the reactive power reference from node p to the shunt side of GUPFC; AQ sh Q is the reactive power imbalance from node p to the shunt side of GUPFC; P nm P is the active power from node n to node m; P and Q are the active and reactive power; AQ nm , AQ nm Q is the active and reactive power imbalance from node n to node m; PEsh=Re(Vsh * ) is the real part of the active power from node p to the shunt side of GUPFC; PEse k =Re(Vse k ·I *nm,k ) is the real part of the active power; Ploss is the power loss in DC side dc =0; AQEx is the real part of the active power imbalance;

[0021] The imbalance equation of STATCOM is as follows:

[0022]

[0023] In the formula, AQ sta , Q is the reactive power of STATCOM, reference reactive power; AQ sta Q is the reactive power imbalance of STATCOM; PEsta=Re(Vsta * ) is the real part of the active power of STATCOM; AQPE is the active power imbalance of STATCOM;

[0024] The imbalance equation of SSSC is as follows:

[0025]

[0026] In the formula, AQPEse is the active power imbalance of SSSC; PEse=Re(Vsssc * ) is the real part of the active power of SSSC.

[0027] Further, the steady-state model of power electronic equipment is simplified as follows:

[0028]

[0029] In the formula, vector F VSC = [ AQ c.dc , AQ f , AQ f , AQ p ] T , vector F GUPFC = [ AQ p / AQsh, AP nm , AQ nm , APEx] T , vector F STATCOM = [AV p / AQsh, APesta] T , vector F SSSC = [AP nm / AQ nm , APesta] T ; x VSC , x GUPFC , x STATCOM and x SSSC represent the bus voltages of the power electronic equipment, i.e. and f VSC , f GUPFC , f STATCOM , f SSSC are multivariate functions of x VSC , x GUPFC , x STATCOM and x SSSC .

[0030] Further, the AC system model is given as follows:

[0031]

[0032] where, is the voltage of bus i, j; Y ij is the element of the AC bus admittance matrix in the i-th row and j-th column; P i , Q i are the active and reactive power injections at bus i, respectively; ΔP i and ΔQ i are the active and reactive power imbalances at bus i;

[0033] The simplified form of the AC system model is given as follows:

[0034] F AC = f AC (x AC ) = 0 (7)

[0035] where, F AC = [ΔP, ΔQ] T , x AC is the bus voltage of the AC system; f AC is a function of the voltage V AC ;

[0036] The DC system model is given as follows:

[0037] ΔP dci= P Gi - P Li + P c.dc,i - V dc,i ∑ j V dcj Y dc.ij = 0 (8)

[0038] where V dc,i is the voltage of DC bus i; Y dc.ij is the element of the conductance matrix in the i-th row and j-th column; P Gdc,i , P Ldc,i are the active power generation and active load power on the DC bus i, respectively; ΔP dci is the active power imbalance of the DC system node; V dcj is the voltage of node j; P c.dc,i is the active power of DC bus i;

[0039] The simplified form of the DC system model is as follows:

[0040] F dc = f dc (x dc ) = 0 (9)

[0041] where F dc = [ΔP dc1 , ΔP dc2 , ΔP dc3 ,...] T , x dc represents the DC system bus voltage; f DC is a function of V DC .

[0042] Further, in step 2), the step of calculating the modular local sensitivity matrix comprises:

[0043] 2.1) Import the current control parameters of the power electronic device, and based on the Newton method, solve the steady-state model of the power electronic device in the physical model of each type of power electronic device, to calculate the power flow of each module of the power electronic device;

[0044] 2.2) Based on the power flow of each module of the power electronic device, use the Newton method to solve the AC system model in the physical model of each type of power electronic device, to obtain the AC system power flow, and update the bus voltage of the AC system;

[0045] 2.3) Based on the power flow of each module of the power electronic device, use the Newton method to solve the DC system model in the physical model of each type of power electronic device, to obtain the DC system power flow, and update the bus voltage of the DC system;

[0046] 2.4) Based on the bus voltage of AC / DC system, calculate the modular local sensitivity matrix of target output y with respect to power electronic device control parameter u That is,

[0047]

[0048] where v represents the bus voltage of power electronic device, f PEDs is the unbalanced equation of power electronic device,

[0049] Further, the target value y is as follows:

[0050]

[0051] where, represents the active power current value of tie line i k -j k ; n t is the number of tie lines; is the set value of active power of tie line i k -j k .

[0052] Further, the minimum change amount Δu (k) of power electronic device control parameter at the kth alternating iteration is as follows:

[0053]

[0054] Further, the convergence criterion satisfied by the active power of tie line at the kth iteration is as follows:

[0055] Δy (k) < ε AIM-in (13)

[0056] The convergence criterion satisfied by the alternating iteration power flow at the kth iteration is as follows:

[0057] max | χ (k) - χ (k-1) | < ε AIM (14)

[0058] where, χ represents all state variables in the system, including the bus voltage of AC / DC system and power electronic device; superscript (k) represents the kth iteration; ε AIM is the convergence coefficient of deterministic power flow.

[0059] The technical effect of the present application is self-evident, and the present application provides a remote coordination regulation strategy for power electronic equipment. The strategy first adopts an alternate iteration method (AIM) for preliminary calculation, optimally adjusts the power electronic equipment based on local sensitivity, and ensures that the convergence criteria of deterministic power flow calculation and system adjustment are met. Even if the power electronic equipment in these regions is not adjacent in spatial distribution, the strategy can still accurately regulate the target value of the key region (such as the tie-line active power).

[0060] The present application provides a modular local sensitivity calculation method, which does not require matrix inversion calculation, can reuse the calculation results of the alternate iteration method, and can directly obtain the local sensitivity calculation, thereby improving the solution efficiency of the remote collaborative adjustment strategy. BRIEF DESCRIPTION OF DRAWINGS

[0061] Figure 1 Equivalent circuit diagrams of power electronic equipment: (a) VSC converter station; (b) GUPFC (or UPFC); (c) STATCOM; (d) SSSC;

[0062] Figure 2 Overall flowchart

[0063] Figure 3 Test example introduction

[0064] Figure 4 The absolute value (|Δy|) of the difference between the tie-line active power and the target value when only considering control through the GUPFC.

[0065] Figure 5 The change of tie-line active power with adjustment iteration number when different methods are used in example b: (a) AIM-out; (b) AIM-in; (c) UIM-in. DETAILED DESCRIPTION

[0066] The present application will be further described below in conjunction with examples, but should not be understood as limiting the above-mentioned subject matter of the present application to the following examples. According to ordinary technical knowledge and conventional means in the art, various substitutions and modifications can be made without departing from the above-mentioned technical idea of the present application, and all such substitutions and modifications should be included in the protection scope of the present application.

[0067] Example 1

[0068] Reference Figures 1 to 5 A calculation process and speed-up method considering remote collaborative adjustment of multiple power electronic devices, comprising the following steps:

[0069] 1) Obtain input power system data and establish physical models of various power electronic devices;

[0070] 2) Calculate the modular local sensitivity matrix based on the physical model of power electronic equipment;

[0071] 3) Calculate the target physical quantity y;

[0072] 4) Calculate the minimum change amount Δu of the control parameter of the power electronic equipment at the kth alternating iteration by pseudo-inverse based on the modular local sensitivity matrix and the target physical quantity y (k) , and update the control parameter u (k+1) = u (k) + Δu (k) ;

[0073] 4) Determine whether the active power of the tie line and the alternating iteration power flow at the kth iteration meet the convergence criteria, if yes, output the control parameter of the power electronic equipment, otherwise return to step 2).

[0074] The basic data of the power system includes the topology of the power system, the size and position of the source and load, the type and number of power electronic equipment.

[0075] The physical model of various types of power electronic equipment includes a power electronic equipment steady-state model, an alternating current system model, and a direct current system model.

[0076] The power electronic equipment steady-state model includes the unbalanced equation of the VSC converter station, GUPFC, STATCOM and SSSC.

[0077] The unbalanced equation of the VSC converter station is as follows:

[0078]

[0079] In the formula, P c.dc is the active power flowing from the converter station to the direct current system; ΔP c.dc is the active power imbalance of the converter station flowing to the direct current system; P loss is the active power loss; P c is the active power of node c; ΔP f , ΔQ f are the active power and reactive power imbalance of node f output; P cf , Q cf are the active power and reactive power of node f flowing to node c; P fp , Q fp are the active power and reactive power of node f flowing to node p; Q f is the reactive power output by node f; Q p is the reactive power flowing from the converter station to node p; is the reactive power reference value; ΔQ pThe reactive power imbalance flowing towards node p;

[0080] The unbalance equations of GUPFC are shown below:

[0081]

[0082] In the formula, V p Let be the voltage magnitude at node p; The reference voltage amplitude at node p; ΔV p Q represents the voltage magnitude imbalance at node p. sh The reactive power flowing from node p to the parallel side of GUPFC; ΔQ is the reference value for reactive power flowing from node p to the parallel side of GUPFC; sh P represents the reactive power imbalance flowing from node p to the parallel side of GUPFC; nm Let be the active power flowing from node n to node m; Active and reactive power; ΔP nm ΔQ nm The active and reactive power imbalance from node n to node m; PEsh = Re(Vsh·Ish) * ) represents the real part of the active power flowing from node p to the parallel side of GUPFC; PEse k =Re(Vse) k ·I *nm,k The active power is represented by P, where P is the real part of the active power. The power loss on the DC side is P. dc =0; ΔPEx is the unbalance of the real part of the active power;

[0083] The unbalance equations for STATCOM are shown below:

[0084]

[0085] In the formula, Q sta , For STATCOM reactive power and reference reactive power; ΔQ sta The reactive power imbalance of STATCOM; PEsta = Re(Vsta·Ista) * ) represents the real part of the active power of STATCOM; ΔPE represents the active power imbalance of STATCOM;

[0086] The unbalance equations for SSSC are shown below:

[0087]

[0088] In the formula, ΔPEse is the active power imbalance of SSSC; PEse=Re(Vsssc·Isssc) *) is the real part of the SSSC active power.

[0089] The steady-state model of the power electronics equipment is simplified as follows:

[0090]

[0091] where the vector F VSC = [ΔP c.dc , ΔP f , ΔQ f , ΔQ p ] T , the vector F GUPFC = [ΔV p / ΔQsh, ΔP nm , ΔQ nm , ΔPEx] T , the vector F STATCOM = [ΔV p / ΔQsh, ΔPEsta] T , the vector F SSSC = [ΔP nm / ΔQ nm , ΔPEsta] T ; x VSC , x GUPFC , x STATCOM and x SSSC represent the bus voltage of the power electronics equipment, i.e. and f VSC , f GUPFC , f STATCOM , f SSSC are multivariate functions of x VSC , x GUPFC , x STATCOM and x SSSC .

[0092] The AC system model is shown as follows:

[0093]

[0094] where, is the voltage of bus i, j; Y ij is the element of the AC bus admittance matrix in the i-th row and the j-th column; P i , Q i are the active and reactive power injections at bus i, respectively; ΔP i and ΔQ i are the active and reactive power imbalances at bus i;

[0095] The simplified form of the AC system model is as follows:

[0096] FAC = f AC (x AC ) = 0 (7)

[0097] where F AC = [ΔP, ΔQ] T , x AC is the bus voltage of the AC system; f AC is a function of the voltage V AC ;

[0098] The DC system model is shown as follows:

[0099] ΔP dci = P Gi - P Li + P c.dc,i - V dc,i ∑ j V dcj Y dc.ij = 0 (8)

[0100] where V dc,i is the voltage of the DC bus i; Y dc.ij is the element of the i-th row and j-th column of the conductance matrix; P Gdc,i , P Ldc,i are the active power of the generation and the active power of the load on the DC bus i, respectively; ΔP dci is the active power imbalance of the DC system node; V dcj is the voltage of node j; P c.dc,i is the active power of the DC bus i.

[0101] The simplified form of the DC system model is as follows:

[0102] F dc = f dc (x dc ) = 0 (9)

[0103] where F dc = [ΔP dc1 , ΔP dc2 , ΔP dc3 , …] T , x dc represents the bus voltage of the DC system; f DC is a function of V DC .

[0104] In step 2), the step of calculating the modular local sensitivity matrix comprises:

[0105] 2.1) Import the current control parameters of power electronic devices, and based on the Newton method, solve the steady-state model of power electronic devices in the physical model of various types of power electronic devices, to calculate the power flow of each module of the power electronic device;

[0106] 2.2) Based on the power flow of each module of the power electronic device, use the Newton method to solve the AC system model in the physical model of various types of power electronic devices, to obtain the AC system power flow, and update the bus voltage of the AC system;

[0107] 2.3) Based on the power flow of each module of the power electronic device, use the Newton method to solve the DC system model in the physical model of various types of power electronic devices, to obtain the DC system power flow, and update the bus voltage of the DC system;

[0108] 2.4) Based on the bus voltage of the AC and DC systems, calculate the modularized local sensitivity matrix of the target output y with respect to the control parameters u of the power electronic device That is:

[0109]

[0110] Where v represents the bus voltage of the power electronic device, f PEDs is the unbalanced equation of the power electronic device,

[0111] The target value y is as follows:

[0112]

[0113] Where, represents the current value of the active power of the tie line i k -j k ; n t is the number of tie lines; is the set value of the active power of the tie line i k -j k

[0114] The minimum change amount Δu of the control parameters of the power electronic device at the kth alternating iteration is as follows: (k)

[0115]

[0116] The convergence criterion satisfied by the active power of the tie line at the kth iteration is as follows:

[0117] Δy (k) < ε AIM-in (13)

[0118] The convergence criterion satisfied by the alternating iteration power flow at the kth iteration is as follows:​​

[0119] max |x (k) -χ (k-1) | <ε AIM (14)

[0120] wherein, χ denotes all state variables in the system, including bus voltages of AC and DC systems and power electronic devices; superscript (k) denotes the kth iteration; ε AIM is the convergence coefficient of deterministic power flow.

[0121] Embodiment 2:

[0122] A calculation process and speed-up method considering remote collaborative adjustment of multiple power electronic devices, comprising the following steps:

[0123] 1) Obtain input power system data and establish physical models of various power electronic devices;

[0124] 2) Calculate the modularized local sensitivity matrix based on the physical models of the power electronic devices;

[0125] 3) Calculate the target physical quantity y;

[0126] 4) Based on the modularized local sensitivity matrix and the target physical quantity y, calculate the minimum change amount Δu of the control parameters of the power electronic devices at the kth alternating iteration by pseudo-inverse calculation (k) , and update the control parameters u (k+1) = u (k) + Δu (k) ;

[0127] 4) Determine whether the active power of the tie line and the alternating iteration power flow at the kth iteration both satisfy the convergence criterion, if yes, output the control parameters of the power electronic devices, otherwise return to step 2).

[0128] Embodiment 3:

[0129] A calculation process and speed-up method considering remote collaborative adjustment of multiple power electronic devices, the technical content is the same as that of embodiment 2, further, the basic data of the power system includes the topology structure of the power system, the size and position of the source and load, the type and quantity of the power electronic devices.

[0130] Embodiment 4:

[0131] A calculation process and speed-up method considering remote collaborative adjustment of multiple power electronic devices, the technical content is the same as that of any one of embodiments 2-3, further, the physical models of various power electronic devices include power electronic device steady-state models, AC system models, and DC system models.

[0132] The power electronic device steady-state model includes unbalanced equations of VSC converter station, GUPFC, STATCOM and SSSC.

[0133] Embodiment 5:

[0134] A calculation process and speed-up method considering remote collaborative adjustment of multiple power electronic devices, the technical content being the same as any one of embodiments 2-4, further, the unbalanced equation of the VSC converter station is as follows:

[0135]

[0136] In the formula, P c.dc is the active power flowing from the converter station to the DC system; ΔP c.dc is the active power imbalance of the converter station flowing to the DC system; P loss is the active power loss; P c is the active power of node c; ΔP f , ΔQ f are the active power and reactive power imbalances of node f; P cf , Q cf are the active power and reactive power of node f flowing to node c; P fp , Q fp are the active power and reactive power of node f flowing to node p; Q f is the reactive power output by node f; Q p is the reactive power flowing from the converter station to node p; is the reactive power reference value; ΔQ p is the reactive power imbalance flowing to node p;

[0137] The unbalanced equation of GUPFC is as follows:

[0138]

[0139] In the formula, V p is the voltage amplitude of node p; is the reference voltage amplitude of node p; ΔV p is the voltage amplitude imbalance of node p; Q sh is the reactive power flowing from node p to the parallel side of GUPFC; is the reactive power reference value flowing from node p to the parallel side of GUPFC; ΔQ sh is the reactive power imbalance flowing from node p to the parallel side of GUPFC; P nm is the active power of node n flowing to node m; is the active and reactive power; ΔP nm , ΔQ nmPEsh = Re(Vsh · Ish) is the active power imbalance from node n to node m; PEsh = Re(Vsh · Ish) * ) is the active power real part from node p to GUPFC shunt side; PEse k = Re(Vse k · I *nm,k ) is the active power real part; the power loss on DC side P dc = 0; ΔPEx is the active power real part imbalance;

[0140] The imbalance equation of STATCOM is as follows:

[0141]

[0142] In the formula, Q sta , is the reactive power of STATCOM, the reference reactive power; ΔQ sta is the reactive power imbalance of STATCOM; PEsta = Re(Vsta · Ista * ) is the active power real part of STATCOM; ΔPE is the active power imbalance of STATCOM;

[0143] The imbalance equation of SSSC is as follows:

[0144]

[0145] In the formula, ΔPEse is the active power imbalance of SSSC; PEse = Re(Vsssc · Isssc * ) is the active power real part of SSSC.

[0146] Embodiment 6:

[0147] A calculation process and speed-up method considering remote collaborative adjustment of multiple power electronic devices, the technical content is the same as any one of embodiments 2-5, further, the steady-state model of the power electronic device is simplified as follows:

[0148]

[0149] In the formula, vector F VSC = [ΔP c.dc , ΔP f , ΔQ f , ΔQ p ] T , vector F GUPFC = [ΔV p / ΔQsh, ΔP nm , ΔQ nm , ΔPEx] T , vector F STATCOM= [ΔV p / ΔQsh, ΔPEsta] T , vector F SSSC = [ΔP nm / ΔQ nm , ΔPEsta] T ; x VSC , x GUPFC , x STATCOM and x SSSC represent the bus voltage of power electronic devices, i.e. and f VSC , f GUPFC , f STATCOM , f SSSC are multivariate functions of x VSC , x GUPFC , x STATCOM and x SSSC .

[0150] Embodiment 7:

[0151] A calculation process and speed-up method considering remote collaborative adjustment of multiple power electronic devices, the technical content is the same as any one of embodiments 2-6, further, the AC system model is as follows:

[0152]

[0153] wherein, is the voltage of bus i, j; Y ij is the element of the i-th row and the j-th column of the AC bus admittance matrix; P i , Q i are the active and reactive power injections on bus i, respectively; ΔP i and ΔQ i are the active and reactive power imbalances on bus i;

[0154] The simplified form of the AC system model is as follows:

[0155] F AC = f AC (x AC ) = 0 (7)

[0156] wherein, F AC = [ΔP, ΔQ] T , x AC is the bus voltage of the AC system; f AC is a function of the voltage V AC ;

[0157] The DC system model is as follows:

[0158] ΔP dci= P Gi - P Li + P c.dc,i - V dc,i ∑ j V dcj Y dc.ij = 0 (8)

[0159] where V dc,i is the voltage of DC bus i; Y dc.ij is the element of the conductance matrix in the i-th row and j-th column; P Gdc,i , P Ldc,i are the active power generation and active load power on the DC bus i, respectively; ΔP dci is the active power imbalance of the DC system node; V dcj is the voltage of node j; P c.dc,i is the active power of DC bus i;

[0160] The simplified form of the DC system model is as follows:

[0161] F dc = f dc (x dc ) = 0 (9)

[0162] where F dc = [ΔP dc1 , ΔP dc2 , ΔP dc3 , …] T , x dc represents the DC system bus voltage; f DC is a function of V DC .

[0163] Embodiment 8:

[0164] A calculation process and speed-up method considering remote collaborative adjustment of multiple power electronic devices, the technical content of which is the same as any one of embodiments 2-7, further, in step 2), the step of calculating the modular local sensitivity matrix comprises:

[0165] 2.1) Import the current control parameters of the power electronic device, and solve the steady-state model of the power electronic device in the physical model of each type of power electronic device based on the Newton method, to calculate the power flow of each module of the power electronic device;

[0166] 2.2) Based on the power flow of each module of the power electronic device, use the Newton method to solve the AC system model in the physical model of each type of power electronic device to obtain the AC system power flow, and update the bus voltage of the AC system;

[0167] 2.3) Based on the power flow of each module of the power electronic device, the DC system model in the physical model of each type of power electronic device is solved by using the Newton method to obtain the DC system power flow, and the bus voltage of the DC system is updated;

[0168] 2.4) Based on the bus voltage of the AC and DC systems, the modular local sensitivity matrix of the target output y with respect to the control parameter u of the power electronic device is calculated That is:

[0169]

[0170] Wherein, v represents the bus voltage of the power electronic device, f PEDs is the unbalanced equation of the power electronic device,

[0171] Embodiment 9:

[0172] A calculation process and acceleration method considering remote collaborative adjustment of multiple power electronic devices, the technical content of any one of embodiments 2-8, further, the target value y is as follows:

[0173]

[0174] Wherein, represents the active power current value of the tie line i k -j k ; n t is the number of tie lines; is the set value of the active power of the tie line i k -j k

[0175] Embodiment 10:

[0176] A calculation process and acceleration method considering remote collaborative adjustment of multiple power electronic devices, the technical content of any one of embodiments 2-9, further, the minimum change amount Δu of the control parameter of the power electronic device at the kth alternating iteration (k) is as follows:

[0177]

[0178] Embodiment 11:

[0179] A calculation process and acceleration method considering remote collaborative adjustment of multiple power electronic devices, the technical content of any one of embodiments 2-10, further, the convergence criterion satisfied by the active power of the tie line at the kth iteration is as follows:

[0180] Δy (k) <ε AIM-in (13) ​

[0181] The convergence criterion for the alternating iteration of power flow at the kth iteration is shown as follows:

[0182] max |x (k) - x (k-1) | < ε AIM (14)

[0183] where, χ represents all state variables in the system, including bus voltages of AC and DC systems and power electronic devices; the superscript (k) represents the kth iteration; ε AIM is the convergence coefficient of deterministic power flow.

[0184] Embodiment 12:

[0185] A calculation process and speed-up method considering remote collaborative adjustment of multiple power electronic devices, the steps comprising:

[0186] Step S1: input power system data and establish physical models of various power electronic devices;

[0187] Step S2: perform a loop of one alternating iteration calculation, and calculate a local sensitivity matrix based on modular local sensitivity;

[0188] Step S3: set a set value of a target physical quantity, and calculate a target value y.

[0189] Step S4: obtain a minimum norm solution through pseudo-inverse calculation, and further obtain a minimum change amount Δu (k) of the control parameter of the power electronic device at the kth alternating iteration, and update the parameter.

[0190] Step S5: determine whether the active power of the tie line and the alternating iteration calculation at the kth iteration satisfy the convergence criterion, and if yes, output the control parameter of the power electronic device.

[0191] The features of step S1 are as follows:

[0192] S11: steady-state model of power electronic device

[0193] The equivalent circuits of VSC converter station, GUPFC (or UPFC), STATCOM and SSSC are shown in Figure 1 . Please note that the steady-state model of VSC converter station considers power exchange-related losses, while other models, such as GUPFC (or UPFC), SSSC and STATCOM, ignore these power losses. Considering the positive direction in Figure 1 , the local regulation and imbalance equation of the power electronic device is as follows:

[0194] (1) VSC converter station

[0195] The detailed control parameters of the local regulation of the VSC converter station are given in Table 1.

[0196] Table 1 Control parameters and types of VSC converter station

[0197]

[0198] For the power station, since the AC bus voltage and the complex power S p = P p +jQ p are known, the voltage and of the power station can be calculated by the following equations:

[0199] For the voltage station, the unbalance equation is:

[0200]

[0201] where P c.dc is known, Q s ref is the set value.

[0202] (2) GUPFC (or UPFC)

[0203] For the parallel side, the GUPFC (or UPFC) can control the AC bus voltage amplitude or the injected reactive power For the series side, the GUPFC (or UPFC) can control the power flow The unbalance equation of the GUPFC is:

[0204]

[0205] where PEsh = Re(Vsh·Ish * ) and PEse k = Re(Vse k ·I *nm,k ), the " " in the superscript is the conjugate of the complex number. In addition, the power loss of the DC side is ignored, i.e. P dc ≈0.

[0206] (3) STATCOM

[0207] The STATCOM can control the AC bus voltage amplitude or the injected reactive power The unbalance equation of the GUPFC is:

[0208]

[0209] where PEsta= Re(Vsta• Ista * ), and P dc ≈ 0.

[0210] (4) SSSC

[0211] SSSC can control active power or reactive power The unbalance equation of SSSC is:

[0212]

[0213] where PEse= Re(Vsssc• Isssc * ), and P dc ≈ 0.

[0214] The unbalance equation of power electronic devices in (1)-(4) can be simplified as:

[0215]

[0216] where F VSC = [ΔP c.dc , ΔP f , ΔQ f , ΔQ p ] T , F GUPFC = [ΔV p / ΔQsh, ΔP nm , ΔQ nm , ΔPEx] T , F STATCOM = [ΔV p / ΔQsh, ΔPEsta] T , F SSSC = [ΔP nm / ΔQ nm , ΔPEsta] T , x VSC , x GUPFC , x STATCOM and x SSSC represent the bus voltage of power electronic devices, i.e. and

[0217] S12: AC system model

[0218] The power unbalance equation of bus i in AC system is:

[0219]

[0220] where is the voltage of bus i; Y ij is the element of the jth column of the ith row of the admittance matrix of the AC system; P i , Q i are the active and reactive power injections (loads, generation, and power injection from power electronic devices) at bus i, respectively. And equation (6) can be simplified as:

[0221] F AC = f AC (x AC ) = 0 (7)

[0222] where F AC = [ΔP, ΔQ] T , and x AC is the bus voltage of the AC system.

[0223] S13: DC system model

[0224] The unbalanced equation in the DC system is:

[0225] ΔP dci = P Gi - P Li + P c.dc,i - V dc,i ∑ j V dcj Y dc.ij = 0 (8)

[0226] where V dc,i is the voltage of bus i in the DC system; Y dc.ij is the element of the jth column of the ith row of the conductance matrix; P Gdc,i , P Ldc,i are the active generation power and active load power at bus i in the DC system, respectively. And equation (8) can be simplified as:

[0227] F dc = f dc (x dc ) = 0 (9)

[0228] where F dc = [ΔP dc1 , ΔP dc2 , ΔP dc3 ,…] T , and x dc represents the bus voltage of the DC system.

[0229] 3. According to the calculation process and speed-up method considering remote cooperative adjustment of multiple power electronic devices, the characteristics of step S2 are as follows:

[0230] There are two main methods for remote control, Π-out and Π-in (proposed in this paper), where Π represents the Alternating Iterative Method (AIM), Unified Iterative Method (UIM) or any other iterative solution method of DPF. The process of Π-out is: first, perform DPF (satisfy the convergence criterion of DPF), then adjust the flexible settings (satisfy the convergence criterion of adjustment); The process of Π-in is: first, perform one iteration in DPF, then adjust the power electronic equipment, satisfy the convergence criterion of DPF and adjustment. This patent proposes AIM-in.

[0231] S21: One iteration calculation is performed using the alternating iterative method

[0232] The current control parameters of the power electronic equipment are imported, and then the power flow equations of each module of the power electronic equipment are calculated based on the Newton method. It should be noted that each module is independent of each other, and in theory, parallel calculation can be performed; Then calculate the power injected from the power electronic equipment into the AC system and solve the AC system power flow equation based on the Newton method, then determine the power injected from the VSC converter station into the DC system and solve the DC system power flow equation based on the Newton method; And update the bus voltage of the AC / DC system.

[0233] S22: Solution method of local sensitivity

[0234] In order to realize remote coordinated regulation through power electronic equipment, it is necessary to calculate the local sensitivity matrix of the target output y (such as the active power of the tie line) with respect to the control parameters u of the power electronic equipment

[0235] Traditional local sensitivity

[0236] Local sensitivity matrix obtained by traditional solution method Focus on the coupling relationship of the entire system. The target output y is affected by the state variable χ and u, so y can be expressed as y=y(χ,u). The power flow equation of the entire system is:

[0237] f w (χ,u)=0 (10)

[0238] Where f w is the imbalance equation of the entire system.

[0239] It can be obtained by the following formula:

[0240]

[0241] Modular local sensitivity

[0242] The local sensitivity matrix can also be obtained by modular local sensitivity The modular local sensitivity relies on an intermediate variable, namely the active and reactive power injection s of each bus (from loads, generating equipment, and power electronic equipment), which is used as a bridge to indirectly consider the linear relationship between modules. The relationship between y and u can be expressed as:

[0243]

[0244] Where v represents the bus voltage of the power electronic equipment, and f PEDs The unbalance equation for power electronic equipment is shown in equation (5).

[0245] In fact, calculating the local sensitivity matrix (including traditional local sensitivity matrix) and modular local sensitivity matrix The computational complexity of this method primarily depends on the calculation of the inverse matrix. When using the Unified Iteration Method (UIM), because... The inverse matrix in the matrix has already been calculated, therefore the traditional local sensitivity method is more applicable. However, when using AIM, because... inverse matrix and of The results have been calculated separately for each module, indicating that the modular local sensitivity method is more suitable.

[0246] 4. According to the aforementioned calculation process and speed-up method considering remote coordinated adjustment of multiple power electronic devices, step S3 has the following characteristics:

[0247] Compared to local regulation, in remote regulation, the physical quantities to be controlled in the system are not adjacent to the power electronic equipment, requiring the design of power electronic equipment regulation strategies to adjust the active power of the interconnected lines. If the interconnection line i is determined... k -j k The set value of active power The target value y is determined by the following formula.

[0248]

[0249] in, Indicates the connection line i k -j k The current value of active power; n t Let be the number of tie lines. Since the objective value y = 0, the difference between the objective value y and the target value y is Δy = 0 - y = -y. Clearly, y > 0, and the smaller y is, the more tie lines i... k -j k The closer the actual active power is to the set value.

[0250] 5. The AC / DC power grid remote coordination regulation strategy considering power electronic devices, wherein step S4 is characterized by the following:

[0251] Δy and Δu satisfy Since the dimension of u is always greater than or equal to y, the minimum norm solution is obtained by pseudo-inverse calculation, and then the minimum change amount Δu of the power electronic device control parameter at the kth alternating iteration can be obtained (k) .

[0252]

[0253] The control parameter u of the power electronic device is further updated (k) :u (k+1) =u (k) +Δu (k) .

[0254] 6. The calculation process and speed-up method considering remote collaborative adjustment of multiple power electronic devices, wherein step S5 is characterized by the following:

[0255] It is determined whether the active power of the tie line at the kth iteration satisfies the adjustment convergence criterion:

[0256] Δy (k) <ε AIM-in (15)

[0257] And it is determined whether the two iterations (the kth iteration and the (k-1)th iteration) satisfy the deterministic power flow convergence criterion by the following formula.

[0258] max|χ (k) -χ (k-1) |<ε AIM (16)

[0259] Wherein χ represents all state variables in the system, including bus voltages of AC / DC systems and power electronic devices; the superscript (k) represents the kth iteration; ε AIM is the convergence coefficient of deterministic power flow, usually, ε AIM =10 -6 . If the convergence criterion in formula (16) is not satisfied, the iteration is restarted from the power flow calculation step; otherwise, the final calculation result is output and the calculation process is terminated. ε AIM-in is the adjustment convergence coefficient. In this patent, ε AIM-in =10 -4 . If either formula (16) or formula (15) is not satisfied, steps S2 to S5 are repeated, otherwise the required data is calculated.

[0260] Example 13:

[0261] A verification of the calculation process and acceleration method considering the remote coordinated adjustment of multiple power electronic devices, as follows:

[0262] The examples of this embodiment are intended to illustrate the remote coordinated adjustment characteristics and local adjustment characteristics of power electronic devices. Figure 3 In this example, lines 23-24, 30-38 and 33-37 are the tie lines of the two areas, with rated active power of 1.1 p.u., 2.0 p.u. and 0.2 p.u. respectively. It is assumed that The basic parameters of power electronic devices (such as equivalent impedance, control coefficient, etc.) are derived from “ Ayan, Optimizing reactive power flow of HVDC systems using geneticalgorithm[J].International Journal of Electrical Power&Energy Systems,2014,55:1-12”、“Z.Fan,Z.Yang,K.Xie,etal.General Steady-State Modeling andLinearization of Power Electronic Devices in AC-DC Hybrid Grid[J].IEEETransactions on Power Systems,2021,36(6):5746-5755”, detailed information is shown in Table 2. It should be noted that the control parameter P37-33 of GUPFC can directly adjust the active power of tie line 33-37, while in example a, only P 37-33 of GUPFC (i.e. local adjustment) is considered. Example b further considers the remote coordinated adjustment of power electronic devices.

[0263] The example parameters are derived from MATPOWER, and all tests are performed on a computer with Intel(R) Core(TM) i7-13700K CPU @ 3.40 GHz and 32 GB 6400 MHz DDR5, using MATLAB 2023a.

[0264] Table 2 Parameters of the example

[0265]

[0266] (1) Local adjustment of power electronic devices

[0267] To illustrate the limitations of local regulation, a case study a was designed, which only considers the control parameter P of the GUPFC. 37-33 This parameter can directly adjust the active power of tie lines 33-37 (i.e., local adjustment). Due to the P of GUPFC... 37-33 The impact of the parameters on the active power of the other two tie lines is unclear, therefore the P of GUPFC is... 37-33 Parameters in Adjust near the opposite number (P) 37-33 and (The power direction is opposite), that is, the P of GUPFC 37-33 The parameter changes from 0.11 to 0.2. The active power of the tie line and the absolute value of the difference from the target value (|Δy|) are as follows: Figure 4 As shown.

[0268] according to Figure 4 GUPFC's P 37-33 Setting the minimum value of |Δy| to 0.2756 (not satisfying equation (15)) indicates that only through the P of GUPFC 37-33 Local adjustments are unlikely to bring the active power of the tie line to the target value. Furthermore, with the P of GUPFC... 37-33 The changes indicate that the active power of tie line 33-37 is almost equal to the P of GUPFC. 37-33 While the positive values ​​of the active power of tie lines 23-24 and 30-38 can be obtained, an intuitive relationship between the active power and P37-33 of GUPFC cannot be derived. Therefore, it is unwise to change the active power of tie lines containing non-adjacent (power electronic devices) through local adjustments. Unless the control parameters of the power electronic devices are continuously adjusted manually after each DPF calculation, the impact of power electronic device adjustments on the expected targets is unclear. Therefore, it is necessary to study remote coordinated control strategies to fully leverage the synergistic effects of various power electronic devices, thereby effectively achieving the control targets of all tie lines.

[0269] (2) Remote coordination and regulation of power electronic equipment

[0270] To verify the performance of AIM combined with modular local sensitivity for remote coordinated regulation of power electronic equipment, a case study b was designed. Case study b employed three methods: AIM-out, AIM-in (the method proposed in this patent), and UIM-in. The changes in active power with the number of regulation iterations under different methods are shown in the figure.

[0271] As can be seen from the figures, the results show that the three methods can all achieve the remote coordinated regulation of power electronic devices. In addition, as can be seen from the figures, AIM-in requires a total of 22 regulation iterations, but is the most efficient (1.11 seconds) in achieving remote coordinated regulation. Moreover, regardless of the method used, the green area in the figures shows that some fine-tuning is required to achieve the target under the same convergence criterion (here, ε AIM-in = 10 -4 ). Furthermore, if ε AIM-in is appropriately increased, the number of regulation iterations can be reduced.

Claims

1. A computing process and acceleration method considering remote collaborative adjustment of multiple power electronic devices, characterized in that, The method comprises the following steps: 1) obtaining input power system data and establishing physical models of various power electronic devices; 2) calculating a modular local sensitivity matrix based on the physical models of the power electronic devices; 3) calculating a target physical quantity y; 4) Based on the modular local sensitivity matrix and the target physical quantity y, the minimum change amount Δu of the power electronic device control parameter at the kth alternating iteration is calculated by pseudo-inverse calculation (k) , and the control parameter u is updated (k+1) = u (k) + Δu (k) ; 4) determining whether the active power of the tie line and the alternating iteration power flow at the kth iteration satisfy the convergence criteria, and if so, outputting the control parameters of the power electronic device, otherwise returning to step 2); In step 2), the step of calculating the modular local sensitivity matrix comprises: 2.1) importing the current control parameters of the power electronic device, and based on the Newton method, solving the power electronic device steady-state model in the physical model of various power electronic devices to calculate the power flow of each module of the power electronic device; 2.2) based on the power flow of each module of the power electronic device, using the Newton method to solve the alternating current system model in the physical model of various power electronic devices to obtain the alternating current system power flow, and updating the bus voltage of the alternating current system; 2.3) based on the power flow of each module of the power electronic device, using the Newton method to solve the direct current system model in the physical model of various power electronic devices to obtain the direct current system power flow, and updating the bus voltage of the direct current system; 2.4) Based on the AC / DC system bus voltage, calculate the modular local sensitivity matrix of the target output y with respect to the power electronic device control parameters u That is: where v represents the bus voltage of the power electronic device, f PEDs is the unbalanced equation for the power electronic device, χ represents all state variables in the system, including the AC-DC system and the bus voltage of the power electronic device; f AC is a function related to the AC system bus voltage; s is the active and reactive power injection of each bus.

2. The computing procedure and acceleration method considering the remote coordination of multiple power electronic devices according to claim 1, characterized in that, The basic data of the power system includes the topological structure of the power system, the size and position of the source and load, the type and quantity of the power electronic device.

3. The computing procedure and acceleration method of considering the remote coordination of multiple power electronic devices according to claim 1, wherein, The physical model of various power electronic devices includes a power electronic device steady-state model, an alternating current system model, and a direct current system model. The power electronic device steady-state model includes the unbalanced equations of VSC converter stations, GUPFC, STATCOM, and SSSC.

4. The computing procedure and speed-up method considering remote coordination of multiple power electronic devices according to claim 3, wherein, The unbalanced equation of the VSC converter station is as follows: where P c.dc is the active power flowing from the converter station to the DC system; ΔP c.dc is the active power imbalance flowing from the converter station to the DC system; P loss is the active power loss; P c is the active power at node c; ΔP f , ΔQ f is the active power, reactive power imbalance at node f; P cf , Q cf is the active power, reactive power flowing from node f to node c; P fp , Q fp is the active power, reactive power flowing from node f to node p; Q f is the reactive power output at node f; Q p is the reactive power flowing from the converter station to node p; is the reactive power reference; ΔQ p is the reactive power imbalance flowing to node p; The unbalanced equation of the GUPFC is as follows: where V p is the voltage magnitude at node p; is the reference voltage magnitude at node p; ΔV p is the voltage magnitude imbalance at node p; Q sh is the reactive power flowing from node p to the shunt side of the GUPFC; is the reference value of the reactive power flowing from node p to the shunt side of the GUPFC; ΔQ sh is the reactive power imbalance from node p to the shunt side of the GUPFC; P nm is the active power flowing from node n to node m; is the reference value of the active and reactive power; ΔP nm , ΔQ nm is the active and reactive power imbalance from node n to node m; PEsh = Re(Vsh * ) is the real part of the active power flowing from node p to the shunt side of the GUPFC; PEse K = Re(Vse K x I nm,K ) is the real part of the active power; P dc losses in the DC side = 0; ΔPEx is the real part of the active power imbalance; The unbalanced equation of the STATCOM is as follows: where Q sta , is the reactive power of STATCOM, reference reactive power; AQ sta is the reactive power imbalance of STATCOM; PEsta = Re(Vsta · Ista * ) is the active power real part of STATCOM; AQPEsta is the active power imbalance of STATCOM; The unbalanced equation of the SSSC is as follows: where ΔPEse is the active power imbalance of the SSSC; PEse = Re(Vsssc·Isssc * ) is the real part of the active power of the SSSC.

5. The computing procedure and speed-up method considering the remote coordination of multiple power electronic devices according to claim 4, wherein, The power electronic device steady-state model is simplified as follows: where the vector F VSC = [ΔP c.dc , ΔP f , ΔQ f , ΔQ p ] T , the vector F GUPFC = [ΔV p / ΔQsh, ΔP nm , ΔQ nm , ΔPEx] T , the vector F STATCOM = [ΔV p / ΔQsta, ΔPEsta] T , the vector F SSSC = [ΔP nm / ΔQ nm , ΔPEse] T ; x VSC , x GUPFC , x STATCOM and x SSSC represent the bus voltage of the power electronics device, i.e. and f VSC , f GUPFC , f STATCOM , f SSSC are multivariate functions in x VSC , x GUPFC , x STATCOM and x SSSC .

6. The computing procedure and speed-up method of considering the remote coordination of multiple power electronic devices according to claim 3, characterized in that, The alternating current system model is as follows: wherein, Vijis the voltage of bus i,j; Y ij Yijis the element of the jth column of the ith row of the admittance matrix; P i Pj, Qj i Pj, Qj i Pj, Qj i Pj, Qj The simplified form of the alternating current system model is as follows: F AC = f AC (x AC ) = 0 (7) where F AC = [ΔP, ΔQ] T , x AC is the bus voltage of the AC system; f AC is a function of x AC . The direct current system model is as follows: ΔP dci = P Gdc,i - P Ldc,i + P c.dc,i - V dc,i ∑ j V dcj Y dc.ij = 0 (8) where V dc,i is the voltage of the DC bus i; Y dc.ij is the element of the admittance matrix in the i-th row and j-th column; P Gdc,i , P Ldc,i are the active generation and load power on the DC bus i, respectively; ΔP dci is the active power imbalance at the DC system node; V dcj is the voltage of node j; P c.dc,i is the active power of the DC bus i; The simplified form of the direct current system model is as follows: F dc = f dc (x dc ) = 0 (9) where F dc = [ΔP dc1 , ΔP dc2 , ΔP dc3 ,...] T , x dc represents the DC system bus voltage; f dc is a function of x dc .

7. The computing procedure and acceleration method of considering the remote coordination of multiple power electronic devices according to claim 1, wherein, The target value y is as follows: wherein, denotes the tie line i k - j k the current value of the active power of the tie line i t is the number of tie lines; denotes the tie line i k - j k the set value of the active power of the tie line i 8. The computing procedure and acceleration method of considering the remote coordination of multiple power electronic devices according to claim 1, wherein, minimum variation of the power electronic device control parameter at the kth alternate iteration Δu (k) As shown below:

9. The computing procedure and speed-up method of considering the remote coordination of multiple power electronic devices according to claim 1, wherein, The convergence criteria satisfied by the active power of the tie line at the kth iteration is as follows: Δy (k) <ε AIM-in (13) where ε AIM-in is the adjusted convergence coefficient; The convergence criteria satisfied by the alternating iteration power flow at the kth iteration is as follows: The convergence criteria satisfied by the alternating iteration power flow at the kth iteration is as follows: max | x (k) - x (k-1) | < ε AIM (14) where the superscript (k) denotes the kth iteration; ε AIM is the convergence factor of the deterministic power flow.

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