JP2013099132A - Power system control system and power system control method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a power system control system capable of performing efficient power transmission in the whole of a power system.SOLUTION: A command value calculation part GSa of a system control server GS acquires a voltage Vand a phase θat the same time at an arbitrary node i on a power system Ls, and acquires an active power Pand a reactive power Qof the arbitrary node i from the acquired values. A wiring loss Lbetween arbitrary nodes i and j is calculated from the voltage V, the phase θ, the active power Pand the reactive power Qat the same time to acquire the total wiring loss L of the power system Ls. Such reactive power command values Qand Qthat the total wiring loss L of the power system Ls becomes small to a control target photovoltaic power generation system G2 and a reactive power compensation device G3, is calculated to perform the control of the control target.

Description

  The present invention relates to a power system control system and a power system control method for the purpose of highly efficient operation of the entire power system.

  Conventional main power supply is performed in one direction from a large generator installed in a thermal power plant, a hydropower plant, or a nuclear power plant to a customer side. This power supply includes reactive power for maintaining the voltage on the consumer side in addition to the active power consumed on the consumer side. However, since the previous power plant is geographically far from the customer, the power transmission distance to the customer is long, and the power factor is greatly reduced due to the phase shift caused by reactive power. Therefore, the power factor is improved in the vicinity of the customer by using a phase adjuster such as a phase adjusting reactor or a phase adjusting capacitor. In addition, when reactive power is transmitted over long distances, the loss in the system wiring increases, and the capacity of the system wiring is determined, so that the amount of active power that can be transmitted decreases.

  In recent years, many distributed power sources that obtain power from renewable energy such as sunlight have been linked to the power system, and there is a demand for power associated with power generation from power converters (power conditioners) provided in the distributed power sources. It is starting to flow back to the grid from the house side. However, when such a reverse power flow increases, there is a concern that the voltage value increases at the connection point with the distributed power supply system. When the voltage value rises, the previous phase adjuster operates to suppress the voltage rise, but the amount of adjustment is limited. For example, when the solar power output increases during the daytime (especially in regions where a large amount of solar power is introduced), it may be assumed that the adjustable capacity of the phase adjuster is exceeded. In this case, in order to avoid the deviation of the allowable range of the voltage value increase, the operation is performed so as to suppress the output with the distributed power source, but naturally, the output opportunity is lost to the system.

  Thus, for example, Patent Document 1 proposes that a distributed power source outputs reactive power to the system. A distributed power source installed in a consumer sets determination thresholds such as normal operation, reactive power output, output suppression, and disconnection in accordance with the voltage value at the connection point with the grid. And if the voltage value of a connection point rises at the time of a normal driving | operation, it will switch to the control which outputs reactive power before output suppression, and an output opportunity loss will not arise as much as possible. Also, in the same document 1, the determination threshold value is different according to the distance of the consumer from the starting position on the system so that an unfair feeling does not occur in the output opportunity (power sale opportunity) due to the geographical difference of the consumer. I have to.

  Further, for example, in Patent Document 2, a proposal has been made to output reactive power according to active power output from a distributed power source to a system. That is, in the literature 2, reactive power is calculated to reduce the influence (voltage fluctuation) of the active power to be output on the system voltage, and the system voltage can be stabilized by injecting reactive power based on the calculation. It is said.

Japanese Patent No. 4266003 JP 2009-177882 A

  By the way, in the case where power is supplied to the system from a large-scale renewable energy power plant such as a solar plant or wind farm that uses sunlight or wind power, much of the reactive power necessary to maintain the system voltage is saved. It will be supplied from a thermal power plant. As mentioned above, reactive power transmission from remote thermal power plants is lossy and hinders the increase in the amount of active power transmission, so consider the case of generating such a large amount of renewable energy. Therefore, it was necessary to consider performing efficient power transmission in the entire power system.

  Looking at Patent Documents 1 and 2 from this point of view, the technology disclosed in Patent Document 1 considers the behavior of other distributed power sources in the system, normal operation, reactive power output, output suppression, disconnection, etc. Although the determination threshold is changed according to the distance of the customer, the behavior of other power devices other than the distributed power source and the wiring loss are not taken into consideration. It cannot be said that the reactive power control is effectively performed in the entire power system.

  Also in the technology disclosed in Patent Document 2, consideration is not given to the behavior of other distributed power sources (solar power generation system) of the system, the behavior of other power devices other than the distributed power source, wiring loss, etc. Even in this technology, it cannot be said that the reactive power is effectively controlled in the entire power system.

  The present invention has been made to solve the above-described problems, and an object thereof is to provide a power system control system and a power system control method capable of performing efficient power transmission in the entire power system. .

  In order to solve the above-mentioned problem, the invention according to claim 1 is characterized in that measured value acquisition means for acquiring at least voltage and phase at the same time by time synchronous measurement at an arbitrary node on a predetermined power system, and the acquired same value. Power value acquisition means for acquiring active power and reactive power of the arbitrary node using at least the voltage and phase of time, and arbitrary using at least the acquired voltage, phase, active power and reactive power of the arbitrary node at the same time The wiring loss acquisition means for calculating the wiring loss between nodes and acquiring the total wiring loss of the power system, and the output command value of the control target capable of outputting active power or reactive power to the power system, Output command value calculation means for calculating the output command value of the control target so that the total wiring loss of the power system is small, and the control target is controlled based on the calculated output command value That a control control unit as its gist.

  In the present invention, at least the voltage and phase at the same time at an arbitrary node on the power system are acquired, and the active power and reactive power of the arbitrary node are acquired from the acquired value. The wiring loss between arbitrary nodes is calculated from at least the voltage, phase, active power, and reactive power at the same time, and the total wiring loss of the power system can be obtained. Then, an output command value that reduces the total wiring loss of the power system is calculated for a control target capable of system output of active power or reactive power, and the control target is controlled based on the output command value. . As a result, output control is performed so that the total wiring loss of the power system is small in each control target, and thus the transmission efficiency of the power system can be improved.

  According to a second aspect of the present invention, in the power system control system according to the first aspect, the control target is a distributed power source capable of system output of active power and reactive power, and a control capable of system output of reactive power. The output command value calculating means maximizes the active power output from the distributed power supply, while the reactive power output from the distributed power supply, the reactive power output from the phase adjuster, and the power The gist is to calculate the output command value of the controlled object so that the total wiring loss of the system is minimized.

  In the present invention, the distributed power source and the phase adjuster are included as control targets, and the active power output from the distributed power source is maximized while the reactive power output from the distributed power source, the reactive power output from the phase adjuster, An output command value for the controlled object that minimizes the total wiring loss of the power system is calculated, and the controlled object is controlled. As a result, reactive power is preferably injected from distributed power supplies and phase adjusters that are often placed near power consumption areas, reducing the total wiring loss of the power system, and effective power output from the distributed power supply The amount can be increased.

  According to a third aspect of the present invention, in the power system control system according to the first aspect, the control target is a distributed power source capable of system output of active power and reactive power, and a control capable of system output of reactive power. The output command value calculation means includes a phase shifter so as to maximize the active power output from the distributed power source, while minimizing the reactive power output from the phase adjuster and the total wiring loss of the power system. The gist is to calculate the output command value of the control object.

  In this invention, a distributed power source and a phase adjuster are included as objects to be controlled, and the active power output from the distributed power source is maximized, while the reactive power output from the phase adjuster and the total wiring loss of the power system are minimized. The output command value of the controlled object is calculated, and the controlled object is controlled. As a result, reactive power is preferably injected from the phase adjuster that is often placed in the vicinity of the power consumption area to reduce the total wiring loss of the power system, and increase the amount of active power output by the distributed power source. It becomes possible. In this case, the amount of active power output by the distributed power source can be increased by the amount of reactive power output from the phase adjuster increased.

  According to a fourth aspect of the present invention, in the power system control system according to the second or third aspect, the control target further includes a power plant power generation facility that uses fossil fuel, and the output command value calculating means includes The gist of the invention is to calculate the output command value of the control object that minimizes including the active power and reactive power output from the power plant power generation equipment.

  In this invention, a power plant power generation facility that further uses fossil fuel as a control target is included, and an output command value for the control target that minimizes including the active power and reactive power output by the power plant power generation facility is calculated. The controlled object is controlled. As a result, the output of the power plant generator using fossil fuel can be minimized, which can greatly contribute to the reduction of fossil fuel usage and the reduction of carbon dioxide emissions.

  According to a fifth aspect of the present invention, in the power system control system according to any one of the first to fourth aspects, the output command value calculating means calculates the acquired voltage, active power, and reactive power of any node. The gist of the invention is to calculate an output command value of the control target that is used at least and minimizes the amount of time change of one or both of the active power and reactive power.

  In the present invention, the output command value of the control object is calculated so as to be minimized by taking into account the time change amount of one or both of the active power and the reactive power of the arbitrary node, and the control object is controlled. As a result, even if a system voltage drop occurs due to a system fault or the like, it is possible to react quickly and quickly recover the system voltage through the controlled object.

The gist of the invention described in claim 6 is the power system control system according to any one of claims 1 to 5, wherein the output command value to be controlled is a reactive power command value.
In this invention, output control is performed such that the total wiring loss of the power system is reduced for each control target through the reactive power command value, and transmission efficiency of the power system is improved. Further, if only the reactive power command value is used as the output command value, it is easy to calculate the command value and output the command value to the controlled object.

  The gist of the invention described in claim 7 is that, in the power system control system according to any one of claims 1 to 6, the controlled object includes a photovoltaic power generation system as a distributed power source.

  In this invention, a photovoltaic power generation system is included in the controlled object as a distributed power source to be controlled, and transmission efficiency of the power system is improved through the photovoltaic power generation system. Moreover, the effect of control is large by setting the photovoltaic power generation system that is being introduced to be controlled.

  The invention according to claim 8 is the power system control system according to any one of claims 1 to 7, wherein the measurement value acquisition means acquires the voltage and phase at the same time in the arbitrary node. Is the gist.

  In the present invention, acquisition of the voltage and phase at the same time at any node is performed, and acquisition of the current and phase is not performed. In other words, if real and imaginary components of admittance are acquired and held as system coefficient data, it is possible to calculate active power, reactive power, wiring loss, and the like without measuring current and phase. In this case, no current measuring means is required.

  The invention according to claim 9 is the power system control system according to any one of claims 1 to 7, wherein the measurement value acquisition means includes the voltage and phase at the same time at the arbitrary node, and the current and The gist is to obtain the phase.

  In the present invention, acquisition of voltage and phase, current and phase at the same time at an arbitrary node is performed. That is, by measuring the current and phase in addition to the measurement of voltage and phase, it is possible to calculate active power, reactive power, wiring loss, and the like from each measured value. In this case, it is not necessary to acquire / hold the real number / imaginary number component of admittance as system coefficient data, and the calculation load related to this is reduced.

  The invention according to claim 10 obtains at least the voltage and phase at the same time by time synchronization measurement at an arbitrary node on a predetermined power system, and uses at least the acquired voltage and phase at the same time to Acquire active power and reactive power, calculate wiring loss between arbitrary nodes using at least the acquired voltage, phase, active power and reactive power at the same time of the arbitrary node, and acquire the total wiring loss of the power system The output command value of the control target capable of outputting active power or reactive power to the power system, and calculating the output command value of the control target such that the total wiring loss of the power system is small, It is an electric power system control method for controlling the controlled object based on the calculated output command value.

  In the present invention, similarly to the first aspect, the transmission efficiency of the power system can be improved.

  ADVANTAGE OF THE INVENTION According to this invention, the power system control system and power system control method which can perform efficient power transmission in the whole power system can be provided.

It is a schematic block diagram of the electric power system in one Embodiment. It is a flowchart for demonstrating the aspect of system | strain control. It is a flowchart for demonstrating the aspect of the system | strain control in another example.

DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, an embodiment of the invention will be described with reference to the drawings.
In the power system Ls of the present embodiment shown in FIG. 1, three-phase AC power having a system frequency generated by the thermal power plant generator G1 is sequentially transmitted to the first system Ls1, the second system Ls2, and the third system Ls3. It has become so. A photovoltaic power generation system G2 as a distributed power source is connected to the first system Ls1, a load (not shown) is connected to the second system Ls2, and a reactive power compensator (SVC) G3 is connected to the third system Ls3. Are interconnected.

  The photovoltaic power generation system G2 linked to the first system Ls1 includes a solar panel that obtains electric power from sunlight, which is renewable energy, and a power converter (power conditioner) (both not shown). . The solar power generation system G2 converts the direct-current power generated by the solar panel into three-phase output power at the system frequency by the power converter and outputs it to the first system Ls1. The reactive power compensator G3 linked to the third system Ls3 generates appropriate reactive power from time to time to maintain the system voltage and frequency, and outputs the generated reactive power to the third system Ls3. These photovoltaic power generation system G2 and reactive power compensator G3 are communicably connected to the system control server GS and controlled by the system control server GS.

The voltage V _i and the phase θ _i measured at the same time of the arbitrary node i on the power system Ls are input to the system control server GS. Specifically, in the power system Ls of FIG. 1, four nodes n1 to n4, in this case, a node n1 to which the power plant generator G1 is linked, a node n2 to which the photovoltaic power generation system G2 is linked, and a load Are synchronized with each other by a time synchronization means using GPS or the like from each of a node n3 to which the reactive power compensator G3 is linked and a voltage V ₁ to the same time V ₁ to Each measurement value of V ₄ and phases θ _{1 to} θ ₄ is input. Incidentally, the power system Ls is provided with a large number of transformers, switches, and the like, and the measuring devices that measure the voltages V _{1 to} V ₄ and the phases θ _{1 to} θ ₄ of the nodes n1 to n4 are connected to the nodes n1. It can respond by installing in a transformer, a switch, etc. which exist in -n4. The measuring device is configured to receive a GPS signal, perform time synchronization measurement, and transmit the measurement value to the system control server GS.

The grid control server GS receives the measured values of the active power P _G2 and reactive power Q _G2 output from the photovoltaic power generation system G2 and the measured value of the reactive power Q _G3 output from the reactive power compensator G3. The The active power P _G2 and reactive powers Q _G2 and Q _G3 are also measured at the same time as the previous voltage phase measurement after time synchronization is achieved by the time synchronization means. And system control server GS performs control which considered the whole electric power system Ls to photovoltaic power generation system G2 and reactive power compensator G3 based on each inputted measurement value.

The system control server GS includes a command value calculation unit GSa that calculates a command value for the control target, in this embodiment, the photovoltaic power generation system G2 and the reactive power compensator G3, by calculating a power flow equation. The command value calculation unit GSa, the time measurement values of the voltage is synchronized V ₁ ~V ₄ and the phase theta ₁ through? ₄ are input and photovoltaic systems G2 and disable the control target of each node n1~n4 The measured values of the active power P _G2 and the reactive powers Q _G2 and Q _G3 are also input from the power compensator G3 in time synchronization. The command value calculation unit GSa is configured to control the photovoltaic power generation system G2 and the reactive power compensator G3 so that the power transmission efficiency in the power system Ls is maximized based on the measured values measured at the same time. , Reactive power command values Q _{G2 — 0} and Q _{G3 — 0} are calculated as reactive powers to be output respectively.

Here, we will make a theoretical consideration. Regarding the calculation of the active power P _i and the reactive power Q _{i at} an arbitrary node i of the power system, first, a current I _ij flowing from the arbitrary node j to the arbitrary node i is obtained. The current I _ij is given by the following equation, assuming that the voltage at the node j is V _j and the admittance between the nodes i and j is Y _ij (a vector in bold notation).

The total current I _i flowing into the node i is obtained from the following equation that takes the sum.

The admittance Y _ij between the nodes i and j has a real part component G _ij and an imaginary part component B _ij .

It is. The real part component G _ij and the imaginary part component B _ij can be obtained relatively easily from the system coefficient data. When the phase at node j is θ _j , voltage V _j is expressed by the following equation.

If the voltage at node i is V _i (bold notation is a vector), the active power P _i and reactive power Q _i of node _i are:

It can be expressed as. Therefore, by the coefficient comparison, the active power P _i is expressed by the following equation:

Can be obtained. The reactive power Q _i is given by

Can be obtained. In addition, in order to obtain the active power P _i and the reactive power Q _i at the node i of the power system using [Equation 6] and [Equation 7], the phase difference between the nodes i and j is necessary. Since the phase value changes every moment, it is necessary to simultaneously measure various measurement values using the above-described time synchronization means such as GPS.

Next, the output active power of the generator connected to the node i is P _Gi , the output reactive power is Q _Gi , the output active power of the photovoltaic power generation system is P _PVi , the output reactive power is Q _PVi , and the output of the reactive power compensator _Assuming that the reactive power is Q _SVCi , the active power consumed by the load is P _Li , and the reactive power is Q _Li , (a) generator node, (b) photovoltaic system node, (c) SVC node, (d) load (E) “Tidal current equation” in a mixed node when these nodes are mixed is as follows. P _i and Q _i are expressed by [Equation 6] and [Equation 7].

(A) Generator node

(B) Solar power generation system node

(C) SVC node

(D) Load node

(E) Mixed node

  Next, in order to solve the above “flow equation”, “system operating conditions” of the power system and “equipment constraint conditions” of power equipment (solar power generation system, reactive power compensator, etc.) connected to the same system It is necessary to consider the “binding conditions”.

“System operation conditions” include (a) line capacity restriction and (b) bus voltage restriction. It is _assumed that the line capacity is P _Ci and the capacity upper limit value is P _Cimax . The voltage lower limit value is V _imin , and the voltage upper limit value is V _imax .

(A) Line capacity restriction

(B) Bus voltage constraint

“Device constraint conditions” include (a) device capacity constraints and (b) power factor constraints. In this case, a photovoltaic power generation system and a reactive power compensator are used as power devices connected to the power system. The equipment capacity of the photovoltaic power generation system connected to node i is S _PVi , the capacity upper limit value is S _PVimax , the power factor is Φ, the device capacity of the reactive power compensator is S _SVCi , and the capacity upper limit value is S _SVCimax . .

(A) Device capacity constraints

(B) Power factor constraint

Note that the equipment capacity S _PVi of the photovoltaic power generation system changes from moment to moment due to variations in solar radiation other than output control.

Next, consider the wiring loss of the power system. When the wiring resistance between the nodes i and j is r _ij and the wiring loss is L _ij , the wiring loss L _ij is expressed by the following equation.

Further, if the active power flowing between the nodes i and j and flowing into the node i is P _ij and the reactive power is Q _ij , the wiring loss L _ij can be transformed as follows. Incidentally, since the active power P _ij and the reactive power Q _ij can be obtained in the process of deriving the active power P _i and the reactive power Q _i described above, the calculation can be saved.

Therefore, the total wiring loss L in the electric power system is expressed by the following equation in consideration of the overlap (wiring reciprocation).

  For the purpose of maximizing the power transmission efficiency of the power system, for example, the objective function F is maximized (MaximizeF) when the control target is a photovoltaic power generation system and a reactive power compensator. Achievement is possible.

Incidentally, in the equation of [Equation 20], the output active power P _PVi of the photovoltaic power generation system is maximized, while the output reactive power Q _PVi of the photovoltaic power generation system, the output reactive power Q _SVCi of the reactive power compensator, and the power An operation is performed to minimize the total wiring loss L of the system.

  Based on the above, the command value calculation unit GSa of the system control server GS according to the present embodiment includes the maximization calculation expression of the various objective functions F and related expressions, the constraint condition of the power system Ls (system operation condition, equipment constraint, etc. Condition) is stored.

Then, the command value calculating unit GSa uses the same time the voltage V ₁ ~V ₄ and the phase theta ₁ through? ₄ of the obtained at each node of the power system Ls n1 to n4, various arithmetic expressions while satisfying the constraints The active powers P _{1 to} P ₄ and reactive powers Q _{1 to} Q ₄ of the nodes n _{1 to} n _{4 at which} the reactive power of the entire power system Ls is optimized from time to time are calculated each time. The command value calculation unit GSa obtains the active power P _G2 from the photovoltaic power generation system G2 (PV) and the reactive power compensator G3 (SVC) obtained at the same time as the voltages V _{1 to} V ₄ and the phases θ _{1 to} θ _4. (P _PVi) and the reactive power Q _G2 (Q _PVi), based on the Q _G3 (Q _SVCi), and the reactive power command value Q _{G2_0} for photovoltaic systems G2 of the control object from the calculated value of the reactive power Q ₂ of the previous , and it calculates the reactive power command value Q _{G3_0} for reactive power compensator G3 of the control object from the calculated value of the reactive power Q _3. The command value calculation unit GSa transmits the reactive power command values Q _{G2 — 0} and Q _{G3 — 0} to the corresponding solar power generation system G2 and reactive power compensator G3, respectively.

Photovoltaic system G2 and the reactive power compensator G3 is command value calculating section reactive power command value sent from GSa Q _{G2_0,} receives the Q _{G3_0,} implement the control based on the finger command value Q _{G2_0,} Q _{G3_0} To do. Photovoltaic system G2 outputs the generated by the control based on the reactive power instruction value Q _{G2_0} output power (active power P _G2 and reactive power Q _G2) to the power system Ls1. Reactive power compensator G3 outputs the reactive power Q _G3 generated by the control based on the reactive power command value Q _{G3_0} to the power system Ls3.

In this way, the reactive power Q _G2 and Q _G3 are injected into the power system Ls from the photovoltaic power generation system G2 and the reactive power compensator G3, which are often arranged in the vicinity of the power consumption area, and installed in a remote location and transmission loss. The injection of reactive power from the power plant generator G1 that increases is reduced. That is, the total wiring loss (L) of the power system Ls is minimized, and the transmission efficiency of the power system Ls is maximized. In this case, the reactive power Q _G2 and Q _G3 of the photovoltaic power generation system G2 and the reactive power compensator _G3 are minimized together with the total wiring loss (L) of the power system Ls. The outputs of reactive power Q _G2 and Q _G3 of reactive power compensator G3 are suppressed as much as possible.

Therefore, it is possible to maximize the active power P _G2 generated by photovoltaic systems G2, it is possible to maximize sellable power. Even when a plurality of photovoltaic power generation systems G2 are separately connected to the power system Ls, a fair reactive power Q _G2 output command is issued. The active power P _{G2 of the} power target is maximized fairly. Moreover, since the reactive power generated by the power plant generator G1 is reduced, it greatly contributes to the efficiency of the operation of the generator G1 and the capacity reduction (miniaturization) of the generator G1.

  The operation for maximizing the power transmission efficiency of the power system Ls of the present embodiment is as shown in the flow shown in FIG. Using time synchronization means such as GPS, it is carried out at any given timing.

In step S1, the same time measurement of the voltage V ₁ ~V ₄ and the phase theta ₁ through? ₄ of each node n1~n4 power system Ls is performed. In addition, measurement of active power and reactive power at the same time in a control target (distributed power supply, phase adjuster, power generation facility, etc.) is performed. In the present embodiment, the photovoltaic power generation system G2 (distributed power supply) and the reactive power compensator G3 (phase adjuster) are controlled, and the measurement of the active power P _G2 and the reactive power Q _G2 of the photovoltaic power generation system G2 Then, the reactive power compensator G3 is measured. As will be described later, a thermal power plant generator G1 (power generation equipment) may be added to the control target.

In step S2, the measurement of the voltage V ₁ ~V ₄ and the phase theta ₁ through? ₄ of n1~n4 the same time when the measurement is transmitted to the system control server GS. Similarly, the measured values of active power P _G2 and reactive powers Q _G2 and Q _G3 measured at the same time are transmitted from the photovoltaic power generation system G2 and reactive power compensator G3 to be controlled to the system control server GS. .

In step S3, using the transmitted measurement values, the command value calculation unit GSa of the system control server GS calculates a power flow equation such as a maximal calculation formula of the objective function F.
In step S4, based on the calculation in step S3, active powers P _{1 to} P ₄ and reactive powers Q _{1 to} Q _{4 of} each node n1 to n4 for which the reactive power of the entire power system Ls is optimal are calculated, and invalid calculating a reactive power command value Q _{G2_0} for photovoltaic systems G2 of the control object from the calculated value of the power Q _2, and the reactive power command value Q _{G3_0} for reactive power compensator G3 of the control object from the calculated value of the reactive power Q ₃ is Is done.

In step S5, the reactive power command values Q _{G2 — 0} and Q _{G3 — 0} calculated in step S4 are transmitted to the photovoltaic power generation system G2 and the reactive power compensator G3 to be controlled.
In step S6, the control target of the solar power generation system G2 and the reactive power compensator G3 each of the reactive power command value Q _{G2_0,} conducted individually controlled based on the Q _{G3_0,} photovoltaic systems G2 and reactive power compensator From the device G3, appropriate reactive powers Q _G2 and Q _G3 are output in the power system Ls from time to time. As a result, the transmission efficiency of the power system Ls can be maximized.

Next, characteristic effects of the present embodiment will be described.
(1) In the system control server GS (command value calculation unit GSa), the voltage V _i and the phase θ _i at the same time at an arbitrary node i on the power system Ls are acquired, and the active power of the arbitrary node i is acquired from the acquired value. P _i and the reactive power Q _i is obtained. The wiring loss L _ij between the arbitrary nodes i and j is calculated from the voltage V _i , phase θ _i , active power P _i and reactive power Q _{i at the} same time, and the total wiring loss L of the power system Ls can be obtained. Become. Then, an output command value (reactive power command value Q _{G2 — 0} , reactive power command value Q _{G2 —0,.} Q _{G3 — 0} ) is calculated, and control of the control target is performed based on the output command value. Thereby, in the photovoltaic power generation system G2 and the reactive power compensator G3 to be controlled, output control is performed such that the total wiring loss L of the power system Ls is reduced, so that the power transmission efficiency of the power system Ls is improved. be able to.

(2) while maximizing the active power P _G2 of solar power generation system G2 is outputted, the reactive power Q _G2 photovoltaic system G2 outputs, Q _G3, the reactive power Q _G output from the reactive power compensator G3, Control target output command values (reactive power command values Q _{G2 — 0} , Q _{G3 — 0} ) that minimize the total wiring loss L of the power system Ls are calculated, and the control target photovoltaic power generation system G2 and reactive power compensator G3 Control is performed. As a result, the reactive power Q _G2 and Q _G3 are preferably injected from the photovoltaic power generation system G2 and the reactive power compensator G3 that are often arranged in the vicinity of the power consumption area, thereby reducing the total wiring loss L of the power system Ls. It is possible to increase the effective power P _G2 output from the solar power generation system G2.

(3) _Since only the reactive power command values Q _{G2 — 0} and Q _{G3 — 0} are calculated and output as output command values of the photovoltaic power generation system G2 and the reactive power compensator G3 to be controlled, the calculation and output can be easily performed. Can do.

(4) The effect of the control is great by setting the photovoltaic power generation system G2 that is being introduced to be controlled.
(5) obtaining at the same time the voltage V _i and the phase theta _i at any node i is performed, obtaining the current and the phase is not performed. That is, if the real and imaginary components G _ij , B _ij, etc. of the admittance Y _ij are acquired as system coefficient data and held in the command value calculation unit GSa, the effective power P _i can be reduced without measuring the current and phase. The power Q _i , wiring loss L, etc. can be calculated. In the present embodiment, no current measuring means is required.

In addition, you may change embodiment of this invention as follows.
-The means for time synchronization used in the above embodiment may be other than GPS. For example, a means for achieving dedicated time synchronization in combination with the power system Ls may be constructed.

  In the above embodiment, the photovoltaic power generation system G2 is associated with the distributed power source and the reactive power compensator G3 is associated with the phase adjuster as the control target of the system control server GS. However, the present invention is not limited to this. For example, in addition to the photovoltaic power generation system G2, other power generation systems provided by customers such as a wind power generation system and a cogeneration system may be used as the distributed power source. In addition to the reactive power compensator G3, a phase adjusting reactor, a phase adjusting capacitor, or the like may be used as the phase adjuster. Further, a power generation facility such as a thermal power plant generator G1 or a hydroelectric power plant generator may be added to the control target.

In the above embodiment, as shown in [Equation 20] as the objective function F, the output active power P _G2 (P _PVi ) of the photovoltaic power generation system G2 is maximized while the output reactive power Q of the photovoltaic power generation system G2 is maximized. _G2 (Q _PVi ), reactive power compensator G3 output reactive power Q _G3 (Q _SVCi ), and a function that minimizes total wiring loss L of power system Ls are used, but objective function F may be changed as appropriate. .

For example, the objective function F shown in the following equation [Equation 21] maximizes the output active power P _G2 (P _PVi ) of the photovoltaic power generation system G2, while the output reactive power Q _G3 (Q _SVCi ) of the reactive power compensator G3. , A function that minimizes the total wiring loss L of the power system Ls.

By using this objective function F, the reactive power Q _G3 (Q _SVCi ) output from the reactive power compensator G3 increases and the share increases, but the reactive power Q _G2 (Q _PVi) output from the photovoltaic power generation system G2 increases. ) Is eliminated, it is possible to further increase the effective power P _G2 (P _PVi ) output by the photovoltaic power generation system G2.

Further, for example, the objective function F shown in the following equation [Equation 22] maximizes the output active power P _G2 (P _PVi ) of the photovoltaic power generation system G2, while the output reactive power Q _G3 (Q of the reactive power compensator G3 _SVCi ), output active power P _Gi and reactive power Q _{Gi of} the thermal power plant generator G1 (power generation equipment), and a function that minimizes the total wiring loss L of the power system Ls.

If this objective function F including the thermal power plant generator G1 as a power generation facility is used as the control target, the output of the thermal power plant generator G1 can be minimized, so the amount of fossil fuel used can be reduced, carbon dioxide Can greatly contribute to the reduction of emissions. In this case, reactive power Q _G2 (Q _PVi ) output from the photovoltaic power generation system G2 may be added to the control target.

Also, for example, the objective function F shown in the following equation [Equation 23] is the active power P at the node i expressed using the voltage V _i , the active power P _i , and the reactive power Q _i of the arbitrary node i of the power system Ls. _This is a function that minimizes the time change amount of _i and the time change amount of the reactive power Q _i .

If this objective function F is used, even if a system voltage drop occurs due to a system fault or the like, the reactive power Q _i can be output promptly and the system voltage can be quickly recovered. It becomes. In addition, if a synchronous generator is connected to the power system Ls, the synchronization power reduced due to an accident or the like is recovered more quickly as a result of the system voltage recovery, so that this point also greatly contributes to system stabilization. Can do. Note that either one of the time change amount of the active power P _{i and} the time change amount of the reactive power Q _i may be used without using both.

  Further, an objective function F other than the above may be set. Furthermore, when a certain objective function F is set in the steady state, and some kind of fluctuation is detected on the system Ls such as an accident, the objective function F is switched to another objective function F, or no power generation is performed during the daytime when solar power is generated. You may make it switch to the objective function F different at night. That is, with the same hardware configuration, it is possible to construct a power system suitable for each requirement by a software change that changes the objective function F. This indicates that the same hardware system can be used in various countries in the world where the power situation is greatly different, but the system operation is more flexible and efficient.

In the above embodiment, the total wiring loss L of the power system Ls is obtained from the voltage V _i , the phase θ _i , the active power P _i , and the reactive power Q _i of the arbitrary node i of the power system Ls, and the total wiring loss L is small. The control target is controlled as described above, but the system configuration may not be limited to the control. For example, the steps up to the total wiring loss L of the power system Ls may be used to apply to a system that creates various power system information including the total wiring loss L as a power flow map.

In the above embodiment, the voltage and its phase are measured by the voltage measuring means, and the current value is calculated from the measured value. However, the current value is directly obtained using the current measuring means for measuring the current and its phase. You may do it. Using a three-phase power balance condition, assuming that the phase current is I _Pi , the phase voltage is V _Pi , and the phase difference of the current with respect to the voltage at node i is Φ _i , the active power P _i and reactive power Q _{i at} node _i are: It is represented by

Or, if the line current is I _Li and the line voltage is V _Li , it is expressed by the following equation.

In order to obtain the active power P _i and the reactive power Q _i at the node i of the power system Ls in [Equation 24] or [Equation 25], a phase difference between voltage and current is required. Since the phase value changes from moment to moment, it is necessary to simultaneously measure various measurement values using time synchronization means such as GPS as described above. By using the current measuring means that can synchronize the time in this way, the real part component G _ij and the imaginary part component B _ij of the admittance Y _ij as system coefficient data represented by [Formula 6], [Formula 7], etc. The holding is unnecessary, and the calculation load related to this is reduced. Incidentally, in the flow for maximizing the power transmission efficiency of the power system Ls, step S1 shown in FIG. 2 is replaced with step S1 ′ shown in FIG. 3, and simultaneous measurement of the current and its phase is added.

Next, a technical idea that can be grasped from the above embodiment and another example will be added below.
(A) a measurement value acquisition means for acquiring at least a voltage and a phase at the same time by time synchronization measurement at an arbitrary node on a predetermined power system;
Power value acquisition means for acquiring active power and reactive power of the arbitrary node using at least the acquired voltage and phase at the same time;
A power change amount calculation means for calculating a time change amount of one or both of the acquired arbitrary node at the same time using the voltage, active power and reactive power at the same time;
The output command value of the control target that is capable of outputting active power or reactive power to the power system, and the control target output command is such that the amount of time change of one or both of the active power and reactive power is small. Output command value calculating means for calculating a value;
A power system control system comprising: system control means for controlling the control object based on the calculated output command value.

  In this configuration, an output command value to be controlled is calculated that minimizes the time change amount of one or both of active power and reactive power of an arbitrary node. As a result, even if a system voltage drop occurs due to a system fault or the like, it is possible to react quickly and quickly recover the system voltage through the controlled object.

(B) Obtain at least the voltage and phase at the same time by time-synchronized measurement at an arbitrary node on the predetermined power system,
Using the acquired voltage and phase at the same time to obtain the active power and reactive power of the arbitrary node,
The wiring loss between arbitrary nodes is calculated using at least the acquired voltage, phase, active power and reactive power at the same time of the arbitrary node, and the total wiring loss of the power system is acquired. Power system information acquisition method.

  In this configuration, the total wiring loss of the power system is acquired from the measured values such as the voltage and phase of any node of the power system, active power, and reactive power. Thereby, it can apply to the system etc. which produce various electric power system information including total wiring loss as a tidal current map.

Ls Power system L Total wiring loss L _ij wiring loss n1 to n4 nodes (i, j arbitrary nodes)
V ₁ ~V ₄ Voltage (V _i Voltage) (measured value)
θ _{1 to} θ ₄ phase (θ _i phase) (measured value)
I _Pi phase current (measured value)
V _Pi phase voltage (measured value)
I _Li line current (measured value)
V _Li line voltage (measured value)
Φ _i phase difference (measured value)
_PG2 active power ( _Pi active power)
Q _G2 , Q _G3 reactive power (Q _i reactive power)
Q _{G2_0} Reactive power command value (output command value)
Q _{G3_0} Reactive power command value (output command value)
G1 Thermal power plant generator (power generation equipment, control target)
G2 Solar power generation system (distributed power supply, control target)
G3 Reactive power compensator (phase adjuster, control target)
GS system control server GSa command value calculation unit (measurement value acquisition means, power value acquisition means, wiring loss acquisition means, output command value calculation means, system control means)

Claims (10)

Measurement value acquisition means for acquiring at least voltage and phase at the same time by time synchronization measurement at an arbitrary node on a predetermined power system;
Power value acquisition means for acquiring active power and reactive power of the arbitrary node using at least the acquired voltage and phase at the same time;
Wiring loss acquisition means for calculating wiring loss between arbitrary nodes using at least the voltage, phase, active power and reactive power at the same time of the acquired arbitrary node, and acquiring the total wiring loss of the power system;
Output command value of the control target capable of outputting active power or reactive power to the power system, and calculating the output command value of the control target such that the total wiring loss of the power system is small A calculation means;
A power system control system comprising: system control means for controlling the control object based on the calculated output command value. In the electric power system control system according to claim 1,
The controlled object includes a distributed power source capable of system output of active power and reactive power, a phase adjuster capable of system output of reactive power,
The output command value calculating means maximizes the active power output from the distributed power supply, while the reactive power output from the distributed power supply, the reactive power output from the phase adjuster, and the total wiring loss of the power system. A power system control system characterized by calculating an output command value of the control object that minimizes the above. In the electric power system control system according to claim 1,
The controlled object includes a distributed power source capable of system output of active power and reactive power, a phase adjuster capable of system output of reactive power,
The output command value calculating means maximizes the active power output from the distributed power supply, while the reactive power output from the phase adjuster and the control target such that the total wiring loss of the power system is minimized. An electric power system control system characterized by calculating an output command value. In the electric power system control system according to claim 2 or 3,
The control object further includes a power plant power generation facility using fossil fuel,
The power command control system, wherein the output command value calculation means calculates an output command value of the control target that is minimized including active power and reactive power output from the power plant power generation equipment. In the electric power system control system of any one of Claims 1-4,
The output command value calculating means uses at least the acquired voltage, active power, reactive power of the arbitrary node, and minimizes the control by taking into account the time variation of one or both of the active power and reactive power. A power system control system characterized by calculating a target output command value. In the electric power system control system according to any one of claims 1 to 5,
The power system control system, wherein the output command value to be controlled is a reactive power command value. In the electric power system control system according to any one of claims 1 to 6,
The control target includes a photovoltaic power generation system as a distributed power source. In the electric power system control system according to any one of claims 1 to 7,
The measurement value acquisition means acquires the voltage and phase at the same time in the arbitrary node. In the electric power system control system according to any one of claims 1 to 7,
The measured value acquisition means acquires the voltage and phase, current and phase at the same time in the arbitrary node. Obtain at least the voltage and phase at the same time by time synchronization measurement at an arbitrary node on the predetermined power system,
Using the acquired voltage and phase at the same time to obtain the active power and reactive power of the arbitrary node,
Calculate the wiring loss between arbitrary nodes using at least the voltage, phase, active power and reactive power at the same time of the acquired arbitrary node to obtain the total wiring loss of the power system,
The output command value of the control object capable of outputting active power or reactive power to the power system, and calculating the output command value of the control object such that the total wiring loss of the power system is small,
A power system control method comprising controlling the control object based on the calculated output command value.