阅读说明：本技术 一种有源配电网中短线路解耦的仿真方法及装置 (Simulation method and device for short circuit decoupling in active power distribution network ) 是由 杜晓东 詹惠瑜 曾四鸣 赵建利 姬艳鹏 冯海燕 王春璞 郭禹伶 于 2021-06-10 设计创作，主要内容包括：本发明涉及一种有源配电网中短线路解耦的仿真方法及装置,包括：根据有源配电网分核并行仿真中相邻计算核心间的延时步长计算有源配电网中增加的分布式电容值,所述增加的分布式电容值并联于短线路两端；对增加分布式电容值的短线路两端之间电路进行仿真计算,并在进行仿真的短线路两端间进行电气量数据交换,实现有源配电网中短线路解耦并进行并行仿真,从而在一定程度上克服配电网输电线路长度太短在配电网并行仿真中的不适用性。(The invention relates to a simulation method and a device for short circuit decoupling in an active power distribution network, which comprises the following steps: calculating an increased distributed capacitance value in the active power distribution network according to a delay step length between adjacent calculation cores in the core-division parallel simulation of the active power distribution network, wherein the increased distributed capacitance value is connected to two ends of a short circuit in parallel; the simulation calculation is carried out on the circuit between the two ends of the short circuit with the distributed capacitance value, and the electric quantity data exchange is carried out between the two ends of the simulated short circuit, so that the decoupling and parallel simulation of the short circuit in the active power distribution network are realized, and the inapplicability of the power distribution network in the parallel simulation of the power distribution network caused by the too short length of the power transmission line of the power distribution network is overcome to a certain extent.)

1. A simulation method for short line decoupling in an active power distribution network is characterized by comprising the following steps:

calculating an increased distributed capacitance value in the active power distribution network according to a delay step length between adjacent calculation cores in the core-division parallel simulation of the active power distribution network, wherein the increased distributed capacitance value is connected to two ends of a short circuit in parallel;

and performing simulation calculation on the circuit between the two ends of the short circuit with the increased distributed capacitance value, and performing electric quantity data exchange between the two ends of the simulated short circuit to realize the decoupling of the short circuit in the active power distribution network and perform parallel simulation.

2. The method of claim 1, wherein the increased distributed capacitance value is calculated as follows:

wherein, delta t is a delay step length, L is the length of a short line in the power distribution network, and L₀A shunt inductance in series with the short circuit, C₀C is the added distributed capacitance value in parallel with the short line.

3. The method of claim 1, wherein exchanging electrical data across the simulated short line comprises:

on the basis of thevenin theorem, computing cores at two ends are respectively equivalent to port voltage and thevenin equivalent impedance;

respectively calculating the voltages at two ends of a short circuit in the active power distribution network by using the port voltage and the Thevenin equivalent impedance, and setting the voltages at two ends of the short circuit in the active power distribution network to be equal to each other to obtain a calculation formula of the voltages at two ends of the short circuit in the active power distribution network;

the calculation formulas of the voltages at the two ends of the short circuit in the active power distribution network are arranged, and an equivalent model at the two ends of the short circuit is obtained;

the current amount data of the two ends of the short line in the active power distribution network is shared in the equivalent model of the two ends of the short line.

4. The method of claim 3, wherein the voltage across the short-circuit in the active power distribution network is calculated as follows:

u_q(t-Δt)+Z_ci_q(t-Δt)＝u_p(t)-Z_ci_p(t)

the left side of the equal sign is the voltage of the upstream end of the short circuit in the active power distribution network in the electromagnetic traveling wave propagation direction, and the right side of the equal sign is the voltage of the downstream end of the short circuit in the active power distribution network in the electromagnetic traveling wave propagation direction;

u_q(t-delta t) is the port voltage of a calculation core at the upstream end of a short line in the electromagnetic traveling wave propagation direction in the active power distribution network at t-delta t, i_q(t-delta t) is the current which flows through thevenin equivalent impedance and is simulated and calculated by the calculation core at the upstream end at t-delta t, u_p(t) is the port voltage of the calculation core at t of the downstream end of the short line in the electromagnetic traveling wave propagation direction in the active power distribution network, i_p(t) is the current which flows through the Thevenin equivalent impedance and is subjected to simulation calculation by a calculation core at the downstream end at t, t is simulation time, delta t is delay step length, Z_cIs thevenin equivalent impedance.

5. The method of claim 3, wherein the equivalent model at both ends of the short line comprises the following calculation:

wherein u is_q(t-delta t) port voltage i of short circuit at upstream end of electromagnetic traveling wave propagation direction in active power distribution network at t-delta t_q(t-delta t) is the current which flows through thevenin equivalent impedance and is simulated and calculated by the calculation core at the upstream end at t-delta t, u_p(t) is the port voltage of the calculation core at t of the downstream end of the short line in the electromagnetic traveling wave propagation direction in the active power distribution network, i_p(t) is the current which flows through the Thevenin equivalent impedance and is subjected to simulation calculation by a calculation core at the downstream end at t, t is simulation time, delta t is delay step length, Z_cIs thevenin equivalent impedance.

6. A simulation device for short line decoupling in an active power distribution network is characterized by comprising:

the calculation module is used for calculating the distributed capacitance value which is added in the active power distribution network and is connected with the short circuit in parallel according to the delay step length between the adjacent calculation cores in the core-division parallel simulation of the active power distribution network;

and the decoupling module is used for performing simulation calculation on two ends of the short circuit with the distributed capacitance value respectively by using the calculation cores, and performing electric quantity data exchange between the calculation cores at the two ends to decouple the short circuit in the active power distribution network and perform parallel simulation.

7. The apparatus of claim 6, wherein the increased distributed capacitance value is calculated as follows:

wherein, delta t is a delay step length, L is the length of a short line in the power distribution network, and L₀A shunt inductance in series with the short circuit, C₀C is the added distributed capacitance value in parallel with the short line.

8. The apparatus of claim 6, wherein the decoupling module is specifically configured to:

on the basis of thevenin theorem, computing cores at two ends are respectively equivalent to port voltage and thevenin equivalent impedance;

respectively calculating the voltages at two ends of a short circuit in the active power distribution network by using the port voltage and the Thevenin equivalent impedance, and setting the voltages at two ends of the short circuit in the active power distribution network to be equal to each other to obtain a calculation formula of the voltages at two ends of the short circuit in the active power distribution network;

the calculation formulas of the voltages at the two ends of the short circuit in the active power distribution network are arranged, and an equivalent model at the two ends of the short circuit is obtained;

the current amount data of the two ends of the short line in the active power distribution network is shared in the equivalent model of the two ends of the short line.

9. The apparatus of claim 8, wherein the voltage across the short-circuit in the active power distribution network is calculated as follows:

u_q(t-Δt)+Z_ci_q(t-Δt)＝u_p(t)-Z_ci_p(t)

the left side of the equal sign is the voltage of the upstream end of the short circuit in the active power distribution network in the electromagnetic traveling wave propagation direction, and the right side of the equal sign is the voltage of the downstream end of the short circuit in the active power distribution network in the electromagnetic traveling wave propagation direction;

u_q(t-delta t) is the port voltage of a calculation core at the upstream end of a short line in the electromagnetic traveling wave propagation direction in the active power distribution network at t-delta t, i_q(t-delta t) is the current which flows through thevenin equivalent impedance and is simulated and calculated by the calculation core at the upstream end at t-delta t, u_p(t) is the port voltage of the calculation core at t of the downstream end of the short line in the electromagnetic traveling wave propagation direction in the active power distribution network, i_p(t) is the current which flows through the Thevenin equivalent impedance and is subjected to simulation calculation by a calculation core at the downstream end at t, t is simulation time, delta t is delay step length, Z_cIs thevenin equivalent impedance.

10. The apparatus of claim 8, wherein the equivalent model for both ends of the short line comprises the following equation:

wherein u is_q(t-delta t) port voltage i of short circuit at upstream end of electromagnetic traveling wave propagation direction in active power distribution network at t-delta t_q(t-delta t) is the current which flows through thevenin equivalent impedance and is simulated and calculated by the calculation core at the upstream end at t-delta t, u_p(t) is the port voltage of the calculation core at t of the downstream end of the short line in the electromagnetic traveling wave propagation direction in the active power distribution network, i_p(t) is the current which flows through the Thevenin equivalent impedance and is subjected to simulation calculation by a calculation core at the downstream end at t, t is simulation time, delta t is delay step length, Z_cIs thevenin equivalent impedance.

Technical Field

The invention relates to the field of decoupling parallel simulation of an active power distribution network, in particular to a method and a device for simulating short circuit decoupling in the active power distribution network.

Background

In order to improve the simulation speed, the active power distribution network needs to be subjected to partition decoupling, different areas are placed in separate computing cores, and simulation calculation is carried out at the same time, so that the core-division parallel simulation is realized.

The core-division parallel simulation mode of the power distribution network is to decouple originally mutually coupled systems for operation, the calculation results of each calculation core need to be exchanged and transmitted according to a uniform calculation step length so as to ensure the convergence of the simulation result, the power distribution network generally adopts a power line carrier communication mode, so that the medium for exchanging and transmitting the calculation result information is a power transmission line, in order to ensure that each calculation core can be given sufficient calculation completion time, the length of the line cannot be too short, and a certain line length requirement exists, while in the power distribution network, the power transmission line is generally short, generally 6-20km, if the calculation step length delta t of each calculation core is too short, the information exchange and transmission of the calculation result of the previous calculation core can possibly start before the calculation result of the next calculation core is not obtained due to the too short power transmission line, thereby possibly leading to serious consequences of reduced simulation accuracy and even divergence of results.

Disclosure of Invention

Aiming at the defects of the prior art, the invention provides a simulation method for short line decoupling in an active power distribution network, which comprises the following steps:

calculating an increased distributed capacitance value in the active power distribution network according to a delay step length between adjacent calculation cores in the core-division parallel simulation of the active power distribution network, wherein the increased distributed capacitance value is connected to two ends of a short circuit in parallel;

and performing simulation calculation on the circuit between the two ends of the short circuit with the increased distributed capacitance value, and performing electric quantity data exchange between the two ends of the simulated short circuit to realize the decoupling of the short circuit in the active power distribution network and perform parallel simulation.

Preferably, the calculation of the increased distributed capacitance value is as follows:

wherein, delta t is a delay step length, L is the length of a short line in the power distribution network, and L₀A shunt inductance in series with the short circuit, C₀C is the added distributed capacitance value in parallel with the short line.

Preferably, the exchanging of electrical data between the two ends of the simulated short line includes:

on the basis of thevenin theorem, computing cores at two ends are respectively equivalent to port voltage and thevenin equivalent impedance;

respectively calculating the voltages at two ends of a short circuit in the active power distribution network by using the port voltage and the Thevenin equivalent impedance, and setting the voltages at two ends of the short circuit in the active power distribution network to be equal to each other to obtain a calculation formula of the voltages at two ends of the short circuit in the active power distribution network;

the calculation formulas of the voltages at the two ends of the short circuit in the active power distribution network are arranged, and an equivalent model at the two ends of the short circuit is obtained;

the current amount data of the two ends of the short line in the active power distribution network is shared in the equivalent model of the two ends of the short line.

Further, the calculation formula of the voltage at two ends of the short circuit in the active power distribution network is as follows:

u_q(t-Δt)+Z_ci_q(t-Δt)＝u_p(t)-Z_ci_p(t)

the left side of the equal sign is the voltage of the upstream end of the short circuit in the active power distribution network in the electromagnetic traveling wave propagation direction, and the right side of the equal sign is the voltage of the downstream end of the short circuit in the active power distribution network in the electromagnetic traveling wave propagation direction;

u_q(t-delta t) is the port voltage of a calculation core at the upstream end of a short line in the electromagnetic traveling wave propagation direction in the active power distribution network at t-delta t, i_q(t-delta t) is the current which flows through thevenin equivalent impedance and is simulated and calculated by the calculation core at the upstream end at t-delta t, u_p(t) is the port voltage of the calculation core at t of the downstream end of the short line in the electromagnetic traveling wave propagation direction in the active power distribution network, i_p(t) is the current which flows through the Thevenin equivalent impedance and is subjected to simulation calculation by a calculation core at the downstream end at t, t is simulation time, delta t is delay step length, Z_cIs thevenin equivalent impedance.

Further, the equivalent model at both ends of the short circuit includes the following calculation formula:

wherein u is_q(t-delta t) port voltage i of short circuit at upstream end of electromagnetic traveling wave propagation direction in active power distribution network at t-delta t_q(t-delta t) is the flow-through Thevenin equivalent resistance of the calculation core at the upstream end in simulation calculation at t-delta tCurrent of resistance u_p(t) is the port voltage of the calculation core at t of the downstream end of the short line in the electromagnetic traveling wave propagation direction in the active power distribution network, i_p(t) is the current which flows through the Thevenin equivalent impedance and is subjected to simulation calculation by a calculation core at the downstream end at t, t is simulation time, delta t is delay step length, Z_cIs thevenin equivalent impedance.

Based on the same invention concept, the invention also provides a simulation device for short circuit decoupling in the active power distribution network, which comprises the following steps:

the calculation module is used for calculating the distributed capacitance value which is added in the active power distribution network and is connected with the short circuit in parallel according to the delay step length between the adjacent calculation cores in the core-division parallel simulation of the active power distribution network;

and the decoupling module is used for performing simulation calculation on two ends of the short circuit with the distributed capacitance value respectively by using the calculation cores, and performing electric quantity data exchange between the calculation cores at the two ends to decouple the short circuit in the active power distribution network and perform parallel simulation.

Preferably, the calculation of the increased distributed capacitance value is as follows:

wherein, delta t is a delay step length, L is the length of a short line in the power distribution network, and L₀A shunt inductance in series with the short circuit, C₀C is the added distributed capacitance value in parallel with the short line.

Preferably, the decoupling module is specifically configured to:

on the basis of thevenin theorem, computing cores at two ends are respectively equivalent to port voltage and thevenin equivalent impedance;

respectively calculating the voltages at two ends of a short circuit in the active power distribution network by using the port voltage and the Thevenin equivalent impedance, and setting the voltages at two ends of the short circuit in the active power distribution network to be equal to each other to obtain a calculation formula of the voltages at two ends of the short circuit in the active power distribution network;

the calculation formulas of the voltages at the two ends of the short circuit in the active power distribution network are arranged, and an equivalent model at the two ends of the short circuit is obtained;

the current amount data of the two ends of the short line in the active power distribution network is shared in the equivalent model of the two ends of the short line.

Further, the calculation formula of the voltage at two ends of the short circuit in the active power distribution network is as follows:

u_q(t-Δt)+Z_ci_q(t-Δt)＝u_p(t)-Z_ci_p(t)

the left side of the equal sign is the voltage of the upstream end of the short circuit in the active power distribution network in the electromagnetic traveling wave propagation direction, and the right side of the equal sign is the voltage of the downstream end of the short circuit in the active power distribution network in the electromagnetic traveling wave propagation direction;

u_q(t-delta t) is the port voltage of a calculation core at the upstream end of a short line in the electromagnetic traveling wave propagation direction in the active power distribution network at t-delta t, i_q(t-delta t) is the current which flows through thevenin equivalent impedance and is simulated and calculated by the calculation core at the upstream end at t-delta t, u_p(t) is the port voltage of the calculation core at t of the downstream end of the short line in the electromagnetic traveling wave propagation direction in the active power distribution network, i_p(t) is the current which flows through the Thevenin equivalent impedance and is subjected to simulation calculation by a calculation core at the downstream end at t, t is simulation time, delta t is delay step length, Z_cIs thevenin equivalent impedance.

Further, the equivalent model at both ends of the short circuit includes the following calculation formula:

wherein u is_q(t-delta t) port voltage i of short circuit at upstream end of electromagnetic traveling wave propagation direction in active power distribution network at t-delta t_q(t-delta t) is the current which flows through thevenin equivalent impedance and is simulated and calculated by the calculation core at the upstream end at t-delta t, u_p(t) the end of the calculation core of the short circuit at the downstream end of the electromagnetic traveling wave propagation direction in the active power distribution network at tMouth voltage, i_p(t) is the current which flows through the Thevenin equivalent impedance and is subjected to simulation calculation by a calculation core at the downstream end at t, t is simulation time, delta t is delay step length, Z_cIs thevenin equivalent impedance.

Compared with the closest prior art, the invention has the following beneficial effects:

the invention provides a simulation method and a device for short circuit decoupling in an active power distribution network, which comprises the following steps: calculating an increased distributed capacitance value in the active power distribution network according to a delay step length between adjacent calculation cores in the core-division parallel simulation of the active power distribution network, wherein the increased distributed capacitance value is connected to two ends of a short circuit in parallel; performing simulation calculation on a circuit between two ends of the short circuit with the increased distributed capacitance value, and performing electric quantity data exchange between the two ends of the simulated short circuit to realize short circuit decoupling and parallel simulation in the active power distribution network; the invention improves the traditional distributed parameter long line decoupling method, and provides a short line decoupling simulation method based on a characteristic line, namely, the traveling wave transmission time is prolonged by a method of distributing capacitance, so that the inapplicability of parallel simulation of a long distributed parameter line on a power distribution network is overcome to a certain extent.

Drawings

FIG. 1 is a Bergeron equivalent circuit diagram of a lossless line provided by the present invention;

FIG. 2 is a flow chart of a simulation method for short circuit decoupling in an active power distribution network according to the present invention;

FIG. 3 is a diagram of a short-circuit equivalent calculation model considering distributed capacitance provided by the present invention;

FIG. 4 is a diagram of an equivalent model of two ends of a short circuit considering distributed capacitance provided by the present invention;

FIG. 5 is a diagram of IEEE33 node standard arithmetic example characteristic line short circuit partition decoupling provided by the invention;

FIG. 6 is a partial graph of the voltage of a photovoltaic access point in the event of a three-phase fault in an IEEE33 system provided by the present invention;

FIG. 7 is a partial graph of photovoltaic output current for a three-phase fault event for the IEEE33 system provided by the present invention;

FIG. 8 is a photovoltaic injection current error plot for a three-phase fault event for the IEEE33 system provided by the present invention;

FIG. 9 is a voltage error graph for a photovoltaic access point for a three-phase fault event for an IEEE33 system provided by the present invention;

fig. 10 is a diagram of a simulation apparatus for short line decoupling in an active power distribution network according to the present invention.

Detailed Description

The following describes embodiments of the present invention in further detail with reference to the accompanying drawings.

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all, embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Example 1:

the invention provides a simulation method for short circuit decoupling in an active power distribution network, which comprises the following steps of:

step 1: calculating an increased distributed capacitance value in the active power distribution network according to a delay step length between adjacent calculation cores in the core-division parallel simulation of the active power distribution network, wherein the increased distributed capacitance value is connected to two ends of a short circuit in parallel;

step 2: and performing simulation calculation on the circuit between the two ends of the short circuit with the increased distributed capacitance value, and performing electric quantity data exchange between the two ends of the simulated short circuit to realize the decoupling of the short circuit in the active power distribution network and perform parallel simulation.

Aiming at the condition that the line length in the power distribution network does not meet the requirement of core division parallel simulation information transmission time difference of the power distribution network, the improved method has no two points, namely, the line length is increased, so that the information transmission time difference is ensured to be enough, but the method has no practical significance, and the line length of the actual power distribution network cannot be lengthened; and secondly, the information transfer time is increased, namely, the calculation result of the previous calculation core is ensured to be transferred to a position after the calculation of the next calculation core is completed.

Because information in power line carrier communication is transmitted in an electromagnetic wave form, the invention increases the traveling wave transmission time by adding a distributed capacitor method, thereby overcoming the inapplicability of the power distribution network parallel simulation caused by the too short length of the power transmission line of the power distribution network to a certain extent.

In step 1, the calculation formula of the increased distributed capacitance value is as follows:

wherein, delta t is a delay step length, L is the length of a short line in the power distribution network, and L₀A shunt inductance in series with the short circuit, C₀C is the added distributed capacitance value in parallel with the short line.

The step 2 specifically comprises the following steps:

in the present embodiment, considering the short-circuit equivalent calculation model of the distributed capacitance, as shown in fig. 3, x is the line length, dx is the line length infinitesimal, i is the current flowing in the serial branch, and L is₀Is a series branch inductor, R₀Is a series branch resistance, C₀Being parallel distributed capacitors, U₀The voltage across the series branch (the voltage drop in the middle is a function of the line length infinitesimal and can be ignored, so the voltages across the series branch can be set to the same value),in order to be a partial derivative of the current with respect to the length of the line,is the voltage-to-line length partial derivative.

The wave equation is:

assuming that the propagation velocity of the traveling wave is v and the characteristic impedance in the transmission process of the traveling wave is Z_cAccording to the traveling wave propagation principle, the following steps are known:

according to the fixed-step parallel simulation principle, step delay delta t can occur between cores in multi-core parallel, and the wave equation is analyzed by taking two cores as objects. Assuming that the traveling wave propagates forward f at a velocity v₁(x-v Δ t) is the solution of the minimum time of the wave equation for forward propagation of the traveling wave, i.e. the propagation time of one step, and f₂(x + v Δ t) is the solution of the minimum time of the wave equation when the traveling wave propagates backward, i.e., the propagation time of one step, and the solution is described by the voltage current equation as follows:

u (x, t) is so f₁(x-v. DELTA.t) and f₂The (x + v Δ t) subtraction and then the multiplication by Zc is because if the current is understood as traveling wave transmission, the relationship between the voltage traveling wave traveling one step forward and the current traveling wave traveling one step forward is:

u(x-vΔt)＝Z_cf₁(x-vΔt)

similarly, the relationship between the traveling voltage wave propagating forward one step and the traveling current wave propagating forward one step is:

u(x+vΔt)＝-Z_cf₂(x+vΔt)

the voltage value at a certain moment and at a certain position can also be regarded as the sum of the solutions propagated one step forward and one step backward, i.e. the two are added, i.e. the voltage value at a certain moment and at a certain position are summed

u(x,t)＝u(x-vΔt)+u(x+vΔt)

Because the line is uniform and lossless, the electromagnetic wave does not distort or attenuate when propagating forward along the line, when the observer moves with the forward wave along the positive direction x at the speed v (namely x-vt ═ constant), the value i (x, t) Z calculated according to the instantaneous voltage value u (x, t) and the current value i (x, t) observed at the time t at the position x where the observer is located_cU (x, t) is always constant, equal to twice the magnitude of the forward current wave, i.e. 2f₂(x + v Δ t), which is true from the beginning to the end of the line, and the simultaneous multiplication of Z on both sides of the above current equation, as seen from the backward propagation of the traveling wave_cAnd subtracted from the voltage equation as follows:

i(x,t)Z_c-u(x,t)＝2f₂(x+vΔt)Z_c

if the set distance of the distributed parameter line, i.e. the short line in the active power distribution network, is l, no matter the traveling wave is transmitted in the forward direction or in the backward direction, the transmission time can be considered to be constant, i.e. x + v Δ t and x-v Δ t are constants, and the transmission time from the starting end to the tail end is:

equivalent one port voltage u and one Thevenin equivalent impedance Zc by using Thevenin for each calculation core, and port voltage u of the calculation cores in the last step length_i(t- Δ t) plus the voltage drop Z of the Thevenin equivalent impedance of the core_ci_i(t- Δ t) is passed to the next core as the result of the core's calculation, which is equal to the port voltage u at the next step_j(t) voltage drop Z minus Thevenin equivalent impedance of the core_ci_jAnd (t), thereby realizing the transmission of the calculation results among the calculation cores, and enabling the calculation flow to conform to the electrical connection relation. It is this formula that also obtains the distributionFormula parameter line both ends equivalent model can discover that there is not the direct connection of power line at both ends, but through the sharing of current magnitude data, exchanges the electric quantity at both ends to realize parallel simulation, if the observer starts from node i at (t- Δ t) moment, then the t moment reaches node j, then distributed parameter line both ends voltage is:

u_i(t-Δt)+Z_ci_i(t-Δt)＝u_j(t)-Z_ci_j(t)

the negative sign on the right side of the equation indicates that the traveling wave propagates forwards, and t-delta t indicates that the CPU operation time lags by one step, namely, the data of the cut point is the data of the last step of the core connected with the cut point in the step operation time.

Finishing to obtain:

wherein the above formula is represented by_i(t- Δ t) is deduced inversely as follows:

wherein the content of the first and second substances,that is, the following formula

In this embodiment, the two-end equivalent model of the short line of the distributed capacitor is considered, as shown in fig. 4, the two-end equivalent model of the distributed parameter line is not directly connected, and the electric quantities at the two ends are exchanged through current quantity data sharing.

The decoupling of the short circuit in the active power distribution network is realized through the mode, the two computation cores respectively simulate the two ends of the short circuit in the active power distribution network, and the electrical quantities at the two ends are exchanged through current magnitude data sharing, so that the parallel simulation is realized.

Example 2:

the invention provides a best embodiment of a simulation method for short line decoupling in an active power distribution network, which is an IEEE33 node system shown in figure 5, wherein a single distributed photovoltaic is accessed to a node 9, the power distribution network is divided between a node 8 and a node 9, and a characteristic line short line decoupling mode is adopted because the node 8 is connected with the node 9 and the line is short.

An IEEE33 node system is divided into a node decoupling mode from No. 8 and 9 nodes and two parts, the two parts are respectively placed into a No. 1 CPU and a No. 2 CPU for core division parallel simulation, a transient event is set to be a three-phase short-circuit fault at the No. 17 node, and distributed photovoltaic output power is inevitably changed correspondingly. And meanwhile, a serial simulation control group is set, namely, the whole IEEE33 node system is placed in the same computing core for serial simulation.

The voltage of the photovoltaic access point in the three-phase fault event of the IEEE33 system in the embodiment is partially as shown in fig. 6.

The photovoltaic output current of the IEEE33 system three-phase fault event in this embodiment is shown in fig. 7.

The photovoltaic injection current error of the IEEE33 system three-phase fault event in this embodiment is shown in fig. 8.

The voltage error of the photovoltaic access point in the three-phase fault event of the IEEE33 system in this embodiment is shown in fig. 9.

From the operation result, the transient simulation result adopting the short circuit decoupling mode is basically consistent with the traditional serial simulation result, but the analysis of the effect graph after error amplification shows that an error sudden increase phenomenon exists at the switching moment of the transient process, so that the calculation resource sudden increase at the transient switching moment can be inferred to cause the sudden increase of the inter-core communication traffic, and meanwhile, the added distributed capacitance can also generate certain interference on information transmission, and finally the accuracy of the simulation result can be influenced.

Example 3:

based on the same inventive concept, the present invention further provides a simulation apparatus for short line decoupling in an active power distribution network, as shown in fig. 10, including:

the calculation module is used for calculating the distributed capacitance value which is added in the active power distribution network and is connected with the short circuit in parallel according to the delay step length between the adjacent calculation cores in the core-division parallel simulation of the active power distribution network;

and the decoupling module is used for performing simulation calculation on two ends of the short circuit with the distributed capacitance value respectively by using the calculation cores, and performing electric quantity data exchange between the calculation cores at the two ends to decouple the short circuit in the active power distribution network and perform parallel simulation.

The calculation of the added distributed capacitance value is as follows:

wherein, delta t is a delay step length, L is the length of a short line in the power distribution network, and L₀A shunt inductance in series with the short circuit, C₀C is the added distributed capacitance value in parallel with the short line.

The decoupling module is specifically configured to:

on the basis of thevenin theorem, computing cores at two ends are respectively equivalent to port voltage and thevenin equivalent impedance;

respectively calculating the voltages at two ends of a short circuit in the active power distribution network by using the port voltage and the Thevenin equivalent impedance, and setting the voltages at two ends of the short circuit in the active power distribution network to be equal to each other to obtain a calculation formula of the voltages at two ends of the short circuit in the active power distribution network;

the calculation formulas of the voltages at the two ends of the short circuit in the active power distribution network are arranged, and an equivalent model at the two ends of the short circuit is obtained;

the current amount data of the two ends of the short line in the active power distribution network is shared in the equivalent model of the two ends of the short line.

The calculation formula of the voltage at two ends of the short circuit in the active power distribution network is as follows:

u_q(t-Δt)+Z_ci_q(t-Δt)＝u_p(t)-Z_ci_p(t)

the left side of the equal sign is the voltage of the upstream end of the short circuit in the active power distribution network in the electromagnetic traveling wave propagation direction, and the right side of the equal sign is the voltage of the downstream end of the short circuit in the active power distribution network in the electromagnetic traveling wave propagation direction;

u_q(t-delta t) is the port voltage of a calculation core at the upstream end of a short line in the electromagnetic traveling wave propagation direction in the active power distribution network at t-delta t, i_q(t-delta t) is the current which flows through thevenin equivalent impedance and is simulated and calculated by the calculation core at the upstream end at t-delta t, u_p(t) is the port voltage of the calculation core at t of the downstream end of the short line in the electromagnetic traveling wave propagation direction in the active power distribution network, i_p(t) is the current which flows through the Thevenin equivalent impedance and is subjected to simulation calculation by a calculation core at the downstream end at t, t is simulation time, delta t is delay step length, Z_cIs thevenin equivalent impedance.

The equivalent model at two ends of the short circuit comprises the following calculation formula:

wherein u is_q(t-delta t) port voltage i of short circuit at upstream end of electromagnetic traveling wave propagation direction in active power distribution network at t-delta t_q(t-delta t) is the current which flows through thevenin equivalent impedance and is simulated and calculated by the calculation core at the upstream end at t-delta t, u_p(t) is the port voltage of the calculation core at t of the downstream end of the short line in the electromagnetic traveling wave propagation direction in the active power distribution network, i_p(t) is the current which flows through the Thevenin equivalent impedance and is subjected to simulation calculation by a calculation core at the downstream end at t, t is simulation time, delta t is delay step length, Z_cIs thevenin equivalent impedance.

As will be appreciated by one skilled in the art, embodiments of the present invention may be provided as a method, system, or computer program product. Accordingly, the present invention may take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment combining software and hardware aspects. Furthermore, the present invention may take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, and the like) having computer-usable program code embodied therein.

The present invention is described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the application. It will be understood that each flow and/or block of the flow diagrams and/or block diagrams, and combinations of flows and/or blocks in the flow diagrams and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instruction means which implement the function specified in the flowchart flow or flows and/or block diagram block or blocks.

These computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

Finally, it should be noted that: the above embodiments are only for illustrating the technical solutions of the present invention and not for limiting the same, and although the present invention is described in detail with reference to the above embodiments, those of ordinary skill in the art should understand that: modifications and equivalents may be made to the embodiments of the invention without departing from the spirit and scope of the invention, which is to be covered by the claims.