Voltage and reactive power monitoring/control device and method for calculating required reactive power amount for suppressing a fluctuation component and selecting an appropriate equipment

Patent metadata

Field	Value
Publication number	US-10892640-B2
Application number	US-201716099448-A
Country	US
Kind code	B2
Filing date	Mar 21, 2017
Priority date	Jun 20, 2016
Publication date	Jan 12, 2021
Grant date	Jan 12, 2021

Abstract

The voltage and reactive power monitoring/control method includes: measurement data for the power system and data for the system equipment of the power system are used to calculate the system status for the power system at the time of measurement; data for a status estimation calculation result and predicted data for the power generation and load of the power system are used to predictively calculate a system status at a future time from the time of the power system measurement; a fluctuation component is obtained for the predicted value of the data obtained from the power system; the reactive power required to suppress the fluctuation component is obtained, as a required reactive power amount; a reactive power distribution subject is selected from a plurality of pieces of control subject equipment; an output distribution calculation is performed for the required reactive power amount for the selected control subject equipment.

First claim

The invention claimed is:

1. A voltage and reactive power monitoring/control device which is applied to a power system including a control subject equipment capable of adjusting a reactive power, and which monitors and controls a voltage and the reactive power, comprising:
a storage device storing a plurality of programs; and
a processor, the processor configured to execute the plurality of programs to perform steps of:
calculating a fluctuation component of a predicted value of data obtained from the power system;
obtaining the reactive power required for suppressing the fluctuation component as a required reactive power amount;
selecting a reactive power distribution subject equipment among a plurality of control subject equipment;
performing output distribution calculation of the required reactive power amount for the selected power distribution subject equipment;
calculating a control instruction value for each control subject equipment from an output distribution calculation result determined for the selected power distribution subject equipment;
calculating the fluctuation components in a plurality of periods in calculating the fluctuation component of the predicted value of the data obtained from the power system, and
determining the fluctuation component to be suppressed by the reactive power and the fluctuation component to not be suppressed among the fluctuation components in the plurality of periods to obtain the required reactive power amount for the fluctuation component to be suppressed by the reactive power.

2. The voltage and reactive power monitoring/control device according to claim 1 , wherein
the predicted value of the data obtained from the power system is the voltage of the power system, and the required reactive power amount is obtained by conversion into the reactive power by using a conversion coefficient stored in advance.

3. The voltage and reactive power monitoring/control device according to claim 1 , wherein
the reactive power distribution subject selection unit selects the reactive power distribution subject equipment by taking into consideration an adjustment power of the plurality of control subject equipment with respect to the required reactive power amount.

4. The voltage and reactive power monitoring/control device according to claim 1 , wherein
the reactive power distribution subject selection unit selects the reactive power distribution subject by taking into consideration a changeable period of the plurality of control subject equipment and a period of the fluctuation component.

5. The voltage and reactive power monitoring/control device according to claim 4 , wherein the changeable period of the plurality of control subject equipment corresponds to information indicating whether or not suppressing the fluctuation component in a particular period is appropriate for each control subject equipment.

6. The voltage and reactive power monitoring/control device according to claim 1 , wherein, in a case where the control subject equipment is a generator, the output distribution calculation unit distributes the required reactive power according to capabilities of a plurality of the generators to be output distribution subjects.

7. The voltage and reactive power monitoring/control device according to claim 1 , wherein
in a case where the control subject equipment is a discrete reactive power supply device including a mechanical mechanism unit, the output distribution calculation unit distributes the required reactive power so that the number of times of manipulation of the mechanical mechanism unit of a plurality of the reactive power supply devices to be output distribution subjects is not biased.

8. The voltage and reactive power monitoring/control device according to claim 1 , further comprising a display unit visualizing and displaying an operation state of the power system monitored and controlled by the voltage and reactive power monitoring/control device.

9. The voltage and reactive power monitoring/control device according to claim 8 , wherein
the display unit visually displays at least one or more of a time acquired for the data of the system, a relationship between a node voltage and constraint conditions (upper and lower limit values of an operation voltage, a target voltage width, and a target voltage), a probability density of the fluctuation component, and the number of times of manipulation of the reactive power supply device.

10. The voltage and reactive power monitoring/control device according to claim 8 , wherein
the display unit visually displays at least one or more of a distribution status of the required reactive power, a distribution effect by the distribution, a degree of deviation in the case of probability distribution, a frequency of use of each control device, display of the number of times, a relationship between a countermeasure and a band, a countermeasure equipment, and an insufficient capacity.

11. The voltage and reactive power monitoring/control device according to claim 8 , wherein
the display unit visually displays at least one or more of data used for monitoring and controlling by the voltage and reactive power monitoring/control device.

12. The voltage and reactive power monitoring/control device according to claim 1 , wherein
the output instruction unit gives the obtained control instruction value to the control subject equipment to control the power system.

13. The voltage and reactive power monitoring/control device according to claim 1 , wherein
the display unit visually displays at least one or more of an insufficient amount of the reactive power at a prediction time point, a proposal of a countermeasure, a past value and a predicted value of the required reactive power ΔQ for each fluctuation component, and time elapse of a control subject equipment capacity and a required equipment capacity.

14. A voltage and reactive power monitoring/control device which is applied to a power system including a control subject equipment capable of adjusting a reactive power, and which monitors and controls a voltage and the reactive power, comprising:
a storage device storing a plurality of programs; and
a processor, the processor configured to execute the plurality of programs to perform steps of:
calculating a system status at a time of power system measurement by using a measurement data of the power system and data of a system facility of the power system, to obtain a status estimation calculation result;
predicting a future system status from the time of power system measurement by using data of the status estimation calculation result and a prediction data of power generation and load of the power system to obtain a predicted value;
calculating a fluctuation component of a predicted value of data obtained from the power system;
obtaining the reactive power required for suppressing the fluctuation component as a required reactive power amount;
selecting a reactive power distribution subject equipment among a plurality of control subject equipment;
performing output distribution calculation of the required reactive power amount for the selected reactive power distribution subject equipment;
calculating a control instruction value for each control subject equipment from an output distribution calculation result determined for the selected reactive power distribution subject equipment;
calculating the fluctuation components in a plurality of periods in calculating the fluctuation component of the predicted value of the data obtained from the power system, and
determining the fluctuation component to be suppressed by the reactive power and

Assignees

• Hitachi Ltd

Inventors

• Kuroda Eisuke
• Miyake Toshiyuki
• Saito Nao
• Yatsu Masahiro
• Kawahara Taichirou

Classifications

• H02J13/12

  Monitoring network conditions, e.g. electrical magnitudes or operational status · CPC title

• H02J13/13

  characterised by the transmission of data to equipment in the power network · CPC title

• Y02E40/30

  Reactive power compensation · CPC title

• H02J3/16 Primary

  by adjustment of reactive power · CPC title

• H02J3/18

  Arrangements for adjusting, eliminating or compensating reactive power in networks · CPC title