JP2013247785A - Voltage reactive power control system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a VQC system which can achieve voltage control by less apparatus operation.SOLUTION: The voltage reactive power control system is applied to a configuration provided with phase control facilities 6 and 7 for controlling state quantity on a primary side and a secondary side of a first transformer with a tap connected between a high voltage bus line and a medium voltage bus line, and state quantity on a primary side and a secondary side of a second transformer with a tap connected between the medium voltage bus line and a low voltage bus line, respectively. The voltage reactive power control system monitors each state quantity, and adjusts the state quantity within a target value by outputting a control command for a tap position (Tap 1) of the first transformer with a tap, a tap position (Tap 2) of the second transformer with a tap, and the phase control facilities 6 and 7. Out of two control planes, one control plane contains a control content for controlling the phase control facilities 6 and 7, and the other control plane contains a control content for controlling the Tap 2.

Description

  The present invention relates to a voltage reactive power control system.

  In general, in the power system, the voltage of the power and the reactive power change depending on the state of the load. For this reason, when operating the power system, the voltage and reactive power are adjusted within the target values. The adjustment of the voltage and reactive power is performed by controlling the voltage reactive power control device with a voltage reactive power controller (Voltage Reactive Power Controller) device or system.

  As the voltage reactive power control device, a phase adjusting facility such as a power capacitor (SC) or a shunt reactor (ShR) provided in the power system, or a tap of a transformer with a tap is used. The VQC system controls the tap position of the tapped transformer and the phase adjusting equipment based on the voltage and reactive power of the power system, the tap position of the tapped transformer, and the operation information of the phase adjusting equipment, respectively. It is comprised so that electric power may be adjusted within target value (for example, patent document 1).

JP 2010-51097 A

  When installing the VQC system in a substation having three or more voltage levels (V1, V2, V3), generally, a VQC device for high and medium pressure (V1, V2) and a medium and low voltage (V2, V3) In many cases, two VQC devices are used, and each is configured to independently operate a voltage reactive power control device. In this case, since the medium-voltage bus voltage (V2) is controlled by the two VQC devices, there is a possibility that a control command is output at substantially the same time depending on the bus voltage status.

  In addition, there is a possibility that the other VQC device outputs a control command before the disturbance of the power system due to the control command output by one VQC device is settled. At that time, the voltage value and the reactive power value may not fall within the target values. Therefore, either the high / medium pressure VQC device or the medium / low pressure VQC device issues the control command again, and the voltage and the reactive power fall within the target values. The operation of the voltage reactive power control device is frequently performed several tens of times a day. Since the voltage reactive power control device performs maintenance based on the number of operations, there is a problem that the maintenance interval becomes shorter as the number of unnecessary operations increases. Moreover, as described above, unnecessary disturbances are given to the power system due to unnecessary operations.

  In order to deal with such a problem, for example, in Patent Document 1, when the scheduled output time of each VQC device is approaching, the output time of any VQC device is delayed so that it is separated. A method has been proposed. If this method is used, it is considered that the number of operations of the device can be reduced to some extent.

  However, the method of Patent Document 1 follows the conventional control plane assuming two voltage levels, and the mutual influence between the VQC devices cannot be essentially avoided. There was a problem that there was a limit naturally.

  The present invention has been made in view of the above, and an object thereof is to obtain a voltage reactive power control (VQC) system capable of realizing voltage control with fewer device operations.

  In order to solve the above-described problems and achieve the object, the present invention provides a first tapped transformer connected between a high-voltage bus and an intermediate-voltage bus among three buses having different voltage levels of the power system. , A second tapped transformer connected between the medium-pressure bus and the low-voltage bus, and state quantities on the primary side and the secondary side of the first and second tapped transformers, respectively. The present invention is applied to a configuration in which a plurality of phase-adjusting facilities to be controlled are provided, the state quantity is monitored, and a tap position (first tap position) in the first tapped transformer, the second tapped transformer. In the voltage reactive power control system that outputs the control command for the tap position (second tap position) and the phase adjusting equipment to adjust the state quantity within the target value, control of one of the two control planes Controls all phase adjustment equipment on a flat surface And the control content whose control target is the first tap position, and the control content whose control target is the second tap position is included in the other control plane. And

  According to the present invention, there is an effect that voltage control can be realized with fewer device operations.

FIG. 1 is a configuration diagram showing an example of a VQC system according to Embodiment 1 of the present invention. FIG. 2 is a flowchart showing an example of calculation contents executed in the VQC system. FIG. 3 is a diagram illustrating an example of a control plane used when executing the control calculation according to the first embodiment. FIG. 4 is a diagram illustrating an example of a control plane used when executing the control calculation according to the second embodiment. FIG. 5 is a diagram illustrating an example of a control plane used when executing the control calculation according to the third embodiment. FIG. 6 is a diagram illustrating an example of a control plane used when executing the control calculation according to the fourth embodiment. FIG. 7 is a diagram illustrating a general control plane as a comparative example.

  A voltage reactive power control system (hereinafter referred to as “VQC system”) according to an embodiment of the present invention will be described below with reference to the accompanying drawings. In addition, this invention is not limited by embodiment shown below.

Embodiment 1 FIG.
FIG. 1 is a configuration diagram showing an example of a VQC system according to Embodiment 1 of the present invention. The VQC system 11 according to the first embodiment is provided in a power system (such as a substation) having buses (a high-voltage bus 1, an intermediate-voltage bus 2 and a low-voltage bus 3) divided into three voltage levels as shown in the figure, for example. Installed. A tapped transformer 4, which is a first tapped transformer, is connected between the high pressure bus 1 and the medium pressure bus 2, and a second tap is connected between the medium pressure bus 2 and the low pressure bus 3. A tapped transformer 5 which is an attached transformer is connected. A phase adjusting facility 6 is connected to the tertiary side of the tapped transformer 4, and a phase adjusting facility 7 is connected to the tertiary side (tertiary winding) of the tapped transformer 5. Voltage detectors 8, 9, and 10 are connected to the high-voltage bus 1, the medium-voltage bus 2, and the low-voltage bus 3, respectively. 11. 1 illustrates the configuration in which the phase adjusting facilities 6 and 7 are respectively connected to the tertiary windings of the tapped transformers 4 and 5, but any one of the buses in which the phase adjusting facilities 6 and 7 are different from each other. It may be configured to be connected to.

  The VQC system 11 monitors a state quantity of interest, determines whether or not control is necessary based on the state quantity, and performs necessary control. An example of the processing is shown as a flowchart in FIG. In step ST1, the measured values of the bus voltage V1, V2, V3 are taken and their effective values are calculated. In step ST2, a deviation between the effective voltage value calculated in step ST1 and a threshold value defined by a control plane described later is calculated, and each deviation is integrated. In step ST3, an operation determination is made as to whether or not the integral value exceeds a predetermined threshold value, and when the integral value exceeds the threshold value, a control target is selected according to the content determined by the control plane. Execute the process.

  FIG. 3 is a diagram illustrating an example of a control plane used when executing the control calculation according to the first embodiment. The control plane includes two control planes, ie, the control plane 1 and the control plane 2. The control plane 1 determines whether or not to control the tap (Tap 1) in the phase adjusting equipment 6 and 7 and the tapped transformer 4, and the control plane 2 controls the tap (Tap 2) in the tapped transformer 5. The necessity is determined. In each of the control planes 1 and 2, a state quantity of interest, a threshold value thereof, and a dead zone are set on the plane.

  More specifically, on the control plane 1, boundary lines K1 and K2 drawn perpendicularly to the V1 axis (horizontal axis) represent threshold values for determining whether or not the phase adjusting equipments 6 and 7 are required to be controlled. ing. For example, when the bus voltage V1 is located on the right side of the boundary line K1 (that is, when the voltage V1 is larger than the corresponding threshold value), the buses are disconnected by disconnecting capacitors and the like in the phase adjusting equipments 6 and 7. The voltage V1 is controlled to decrease. On the other hand, when the bus voltage V1 is located on the left side of the boundary line K2 (that is, when the bus voltage V1 is larger than the corresponding threshold value), a capacitor or the like in the phase adjusting equipment 6 or 7 is inserted. To increase the bus voltage V1.

  In the control plane 1, boundary lines K3 and K4 drawn perpendicularly to the axis (vertical axis) of V2 represent threshold values for determining whether or not the tap (Tap1) in the tapped transformer 4 needs to be controlled. ing. For example, when the bus voltage V2 is located above the boundary line K3 (that is, when the bus voltage V2 is larger than the threshold value), the tap position of the tapped transformer 4 is changed to change the bus voltage V2. Control the direction to lower. On the other hand, when the bus voltage V2 is located below the boundary line K4 (that is, when the bus voltage V2 is smaller than the corresponding threshold value), the tap position of the tapped transformer 4 is changed to change the bus line. Control to increase voltage V2.

  Similarly, the boundary lines K5 and K6 drawn perpendicularly to the axis (vertical axis) of V3 in the control plane 2 indicate threshold values for determining whether or not the tap (Tap2) in the tapped transformer 5 needs to be controlled. Represents. For example, when the bus voltage V3 is located above the boundary line K5 (that is, when the bus voltage V3 is larger than the corresponding threshold value), the tap position of the tapped transformer 5 is changed to change the bus voltage V3. Control the direction to lower. On the other hand, when the bus voltage V3 is located below the boundary line K6 (that is, when the bus voltage V3 is smaller than the corresponding threshold value), the tap position of the tapped transformer 5 is changed to change the bus Control to increase voltage V3.

  Next, effects of the VQC system according to Embodiment 1 will be described. This will be described with reference to FIGS. 3 and 7. Here, FIG. 7 is a diagram showing a general control plane shown as a comparative example. When the control plane shown in FIG. 7 is used in a three-voltage class configuration as shown in FIG. 1, the phase-adjusting facilities 6 and 7 that are substantially equivalent as control effects are controlled by another control plane. Therefore, as described in the section “Problems to be Solved by the Invention”, control competition between the two (for example, if the voltage of V1 increases, the voltage of V2 also increases (and vice versa)). As a result, the number of times of device operation increases, for example, control in the opposite direction is required separately. Depending on the setting of the threshold, there are some problems such as the fact that control of the phase adjusting equipment may not be implemented even though the operation of the phase adjusting equipment is necessary as a whole. Will occur.

  On the other hand, if the control plane shown in FIG. 3 is used, the phase adjusting equipments 6 and 7 are controlled by the same control plane (control plane 1). Efficient control can be realized with a limited number of operations. Note that which of the phase adjusting equipments 6 and 7 is to be selected may be determined by a separate rule.

  In the first embodiment, as shown in FIG. 1, a plurality of devices are controlled by one VQC device (system). However, the configuration includes one VQC device for each control plane. Also good. The same applies to other embodiments described later.

  In the first embodiment, only the voltage is taken as the state quantity of interest, but the reactive power Q1 can be used instead of the voltage V1 as in the normal VQC system. The same applies to other embodiments described later.

  In the first embodiment, the configuration having two phase adjusting facilities is illustrated, but the present invention can also be applied to a configuration having three or more phase adjusting facilities. In this case, several phase adjusting facilities may be handled in groups of two. The same applies to other embodiments described later.

  In the first embodiment, of the two control planes, the control plane 1 includes the control content for the phase adjusting equipments 6 and 7 and the control content for the tap position (Tap1) in the tapped transformer 4. The control plane 2 includes the control content related to the tap position (Tap2) in the tapped transformer 5, but the relationship between Tap1 and Tap2 may be switched. That is, of the two control planes, one of the control planes includes control contents for which all the phase adjusting equipments are to be controlled and control contents for which the tap positions in one of the tapped transformers are to be controlled. In this way, the remaining control plane may include the control content whose control target is the tap position in the other tapped transformer.

Embodiment 2. FIG.
FIG. 4 is a diagram illustrating an example of a control plane used when executing the control calculation according to the second embodiment. In the first embodiment, FIG. 3 is used as the control plane. However, in the second embodiment, the control calculation is executed using the control plane shown in FIG.

  The control plane 2 in FIG. 3 follows the general idea (focusing on the secondary voltage of the transformer) as tap control, and uses V3 as the state quantity. However, since V3 itself also changes depending on the control on the phase adjusting equipments 6 and 7 and the tap operation (operation of Tap1) in the tapped transformer 4, these control operations and the tap operation (Tap2 of Tap2) in the tapped transformer 5 are performed. (Operation) may compete with each other, and depending on the system configuration, the number of operations (the number of controls) may be increased. The system configuration mentioned here is the difference in voltage class (whether the high-voltage bus is 500 kV or 275 kV, the medium-pressure bus is 275 kV or 154 kV), and which bus is supporting the voltage (which voltage) This is a difference in equipment such as what kind of power generation equipment is connected to the class bus.

  On the other hand, in FIG. 4, the state quantity of interest on the control plane 2 is changed from “V3” to “V3 / V2”, that is, the state quantity (V3) when the tap position of Tap2 is controlled is controlled by the tap position of Tap1. It is changed to a value (V3 / V2) normalized by the state quantity (V2) in the case of the target. It is considered that the state quantity “V3 / V2” is less affected by the operation of other control devices (phase adjusting facilities 6 and 7 and Tap1) than “V3”. Therefore, using this control plane can be expected to reduce the number of operations compared to the first embodiment. In FIG. 4, the state quantity is set to “V3 / V2”. However, even if the state quantity is returned to “V3” and the threshold value to be compared is changed to a function of V2 instead, almost the same control is performed. Can be done. For this reason, such a change is also included in the gist of the second embodiment.

Embodiment 3 FIG.
FIG. 5 is a diagram illustrating an example of a control plane used when executing the control calculation according to the third embodiment. First, in a general conventional control method, V1 and V2 are used for determination when a phase adjusting facility is a control target (see FIG. 7). On the other hand, in Embodiment 1, 2, it changed so that only V1 might be used for determination when phase-adjusting equipment is made into a control object. With this control method, it is possible to avoid contention between controlled objects. However, since both the control methods of the first and second embodiments are methods for adjusting on the highest voltage side (V1) of the voltage class, it is considered that the effect on the voltage fluctuation on the low voltage side (V3) is reduced. .

  Therefore, in the third embodiment, as shown in FIG. 5, the control determination of the phase adjusting equipment is changed to use V2 which is an intermediate voltage between the high voltage side (V1) and the low voltage side (V3). In addition to this, voltage adjustment between V1 and V2 is performed at Tap1, and voltage adjustment between V2 and V3 is performed at Tap2, thereby making it possible to suppress voltage fluctuation as a whole. Become.

  In the method of the third embodiment, the control necessity of the phase adjusting equipment 6 and the phase adjusting equipment 7 is determined by the same state quantity, but the control plane is different. For this reason, for example, the threshold value (V2th1) on the control plane 1 when controlling the phase adjusting equipment 6 is different from the threshold value (V2th2) on the control plane 2 when controlling the phase adjusting equipment 7 (that is, , | V2th1−V2th2 |> ε, ε is a positive real number for giving a significant difference), and the like, it is preferable to avoid control contention. Although the right threshold value in the control plane has been described here, the same applies to the left threshold value, and it is preferable to give a significant difference to the threshold value to avoid control conflict.

Embodiment 4 FIG.
FIG. 6 is a diagram illustrating an example of a control plane used when executing the control calculation according to the fourth embodiment. In the general control method and the above-described first to third embodiments, a method using two control planes is disclosed as voltage control of a system having three voltage classes, but in the fourth embodiment, as shown in FIG. In addition, the control calculation is executed using three control planes.

  In the control plane shown in FIGS. 3 to 5 and FIG. 7, when controlling the phase adjusting equipment 6, 7, the state quantity for performing the control judgment of Tap 1 (tapped transformer 4) or Tap 2 (tapped transformer 5). Therefore, it is considered that Tap control is often caused as a result. That is, it is considered that it is more efficient that tap control can be performed independently of the control of the phase adjusting equipment.

  Therefore, in the fourth embodiment, as shown in FIG. 6, the phase adjusting equipments 6 and 7 are controlled based on V1, Tap1 is controlled using V1 / V2, and Tap2 is controlled using V2 / V3. Has changed. Thereby, tap control is cut off from phase adjustment equipment control and can be performed independently. With this control method, competition between control devices is kept to a minimum, the number of operations can be reduced, and each control device can be used to the maximum extent possible.

  In addition, in the control plane 1 shown in FIG. 6, V1 is used as a state quantity when controlling the phase adjusting equipment, but it is not limited to V1, and even if this is changed to V2 or V3 Good.

  Further, instead of V1, an average value using all of V1 to V3 or an average value of any two of V1 to V3 may be used. In addition, when using an average value, it is preferable to use the average value shown, for example in following Formula so that the contribution of the voltage value in each voltage class may appear uniformly.

(When using all of V1 to V3)
Vave = (V1 / Vref1 + V2 / Vref2 + V3 / Vref3) / 3
V1 to V3: Measurement values (effective values) in each voltage class
Vref1 to Vref3: Nominal voltage value in each voltage class

(When using V1 and V2)
Vave1 = (V1 / Vref1 + V2 / Vref2) / 2

(When using V2 and V3)
Vave2 = (V2 / Vref2 + V3 / Vref3) / 2

(When using V1 and V3)
Vave3 = (V1 / Vref1 + V3 / Vref3) / 2

  As described above, the present invention is useful as a voltage reactive power control system that enables voltage control with fewer device operations.

1 High-voltage bus 2 Medium-pressure bus 3 Low-voltage bus 4 Transformer with tap (first transformer with tap)
5 Tapped transformer (second transformer with tap)
6, 7 Phase adjustment equipment 8, 9, 10 Voltage detector 11 Voltage reactive power control (VQC) system

Claims (10)

Of the three buses having different voltage levels of the power system, the first tapped transformer connected between the high-voltage bus and the medium-voltage bus, and the first bus connected between the medium-voltage bus and the low-voltage bus Applied to a configuration provided with two tapped transformers and a plurality of phase-adjusting facilities for controlling the primary and secondary state quantities of the first and second tapped transformers, respectively. Monitoring the amount, the tap position (first tap position) in the first tapped transformer, the tap position (second tap position) in the second tapped transformer, and the control command for the phase adjusting equipment In a voltage reactive power control system that adjusts the state quantity within a target value by outputting
Of the two control planes, one control plane includes control contents for which all the phase adjusting equipments are to be controlled and control contents for which the first tap position is to be controlled, and the other control plane. The voltage reactive power control system is characterized in that the control content for which the second tap position is controlled is included.   The value normalized by the state quantity when the first tap position is the control target is used as the state quantity when the second tap position is the control target. Voltage reactive power control system. Of the three buses having different voltage levels of the power system, the first tapped transformer connected between the high-voltage bus and the medium-voltage bus, and the first bus connected between the medium-voltage bus and the low-voltage bus Applied to a configuration provided with two tapped transformers and a plurality of phase-adjusting facilities for controlling the primary and secondary state quantities of the first and second tapped transformers, respectively. Monitoring the amount, the tap position (first tap position) in the first tapped transformer, the tap position (second tap position) in the second tapped transformer, and the control command for the phase adjusting equipment In a voltage reactive power control system that adjusts the state quantity within a target value by outputting
Among the two control planes, one control plane has control contents that control the first tap position, and control that controls several phase-adjusting facilities among the plurality of phase-adjusting facilities. And the control content whose control object is the second tap position in the other control plane, and the control content whose control object is the remaining phase adjusting equipment of the plurality of phase adjusting equipments, And a voltage value or reactive power value at the intermediate-pressure bus is used as a state quantity when the phase-adjusting equipment in the one and other control planes is a control target. Control system.   The state quantity when the phase-adjusting equipment is to be controlled is a voltage value at the high-voltage bus, and the state quantity when the first tap position is the control object is a voltage value at the medium-pressure bus, 2. The voltage reactive power control system according to claim 1, wherein a state quantity when the second tap position is a control target is a voltage value in the low-voltage bus.   The state quantity when the phase-adjusting equipment is to be controlled is a voltage value at the high-voltage bus, and the state quantity when the first tap position is the control object is a voltage value at the medium-pressure bus, 3. The voltage reactive power according to claim 2, wherein the state quantity when the second tap position is a control target is a value obtained by normalizing a voltage value at the low-voltage bus with a voltage value at the medium-voltage bus. Control system.   In the case where the phase adjusting equipment is to be controlled, the determination threshold value of the state quantity on the one control plane is different from the determination threshold value of the state quantity on the other control plane. The voltage reactive power control system according to claim 3.   7. The voltage reactive power control system according to claim 4, wherein a reactive power value is used instead of a voltage value as a state quantity in the high-voltage bus. Of the three buses having different voltage levels of the power system, the first tapped transformer connected between the high-voltage bus and the medium-voltage bus, and the first bus connected between the medium-voltage bus and the low-voltage bus Applied to a configuration provided with two tapped transformers and a plurality of phase-adjusting facilities for controlling the primary and secondary state quantities of the first and second tapped transformers, respectively. Monitoring the amount, the tap position (first tap position) in the first tapped transformer, the tap position (second tap position) in the second tapped transformer, and the control command for the phase adjusting equipment In a voltage reactive power control system that adjusts the state quantity within a target value by outputting
Among the three control planes, the first control plane includes the control contents for which all the phase adjusting equipments are controlled, and the second control plane is the control for the first tap position as the control target. A voltage reactive power control system comprising: content, and the third control plane includes control content for controlling the second tap position.   The state quantity when the phase-adjusting equipment is to be controlled is the voltage value at the high-voltage bus, and the state quantity when the first tap position is the control object is the voltage value at the high-voltage bus. And the state quantity when the second tap position is the control target is a value obtained by normalizing the voltage value at the medium-pressure bus with the voltage value at the low-voltage bus. The voltage reactive power control system according to claim 8, wherein:   As a state quantity when the phase-adjusting equipment is to be controlled, instead of the voltage value at the high-voltage bus, each voltage value at the high-voltage bus, the medium-voltage bus, and the low-voltage bus is normalized with the respective nominal voltage value The voltage reactive power control system according to claim 9, wherein an average value of two or more of the measured values is used.

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