Voltage control apparatus, voltage control method, and power regulating apparatus

Patent metadata

Field	Value
Publication number	US-9377803-B2
Application number	US-201213665155-A
Country	US
Kind code	B2
Filing date	Oct 31, 2012
Priority date	Oct 31, 2011
Publication date	Jun 28, 2016
Grant date	Jun 28, 2016

Abstract

A voltage control apparatus includes: an obtaining unit which obtains voltage values at voltage measuring points; a detecting unit which detects a system impedance value; a control quantity calculating unit which calculates, as control quantity, a reactive power value to be output by a power regulating apparatus to prevent at least a voltage value deviating from a predetermined voltage range from deviating from a target voltage value; and a notifying unit which notifies the power regulating apparatus of the control quantity. The control quantity calculating unit calculates the control quantity such that the voltage value at a specific voltage measuring point is substantially equal to the target voltage value, and when all of the voltage values deviating from the target voltage value deviate from the target voltage value in a same direction, only positive or negative reactive power is output by power regulating apparatuses.

First claim

The invention claimed is:

1. A voltage control apparatus which controls a plurality of power regulating apparatuses, each of the plurality of power regulating apparatuses outputting, to a distribution system, positive reactive power or negative reactive power for regulating voltage of the distribution system, the voltage control apparatus comprising:
an obtainer that obtains voltage values at one or more voltage measuring points provided in the distribution system;
a detector that detects a system impedance value of the distribution system between a substation and each of the plurality of power regulating apparatuses;
a control quantity calculator that, when the one or more voltage measuring points include a voltage measuring point which has a voltage value deviating from a predetermined voltage range, calculates a value as a control quantity to prevent at least the voltage value deviating from the predetermined voltage range at the voltage measuring point from deviating from a target voltage value set within the predetermined voltage range, the value calculated as the control quantity corresponding to a value of the reactive power to be output by each of the plurality of power regulating apparatuses; and
a notifier that notifies each of the plurality of power regulating apparatuses of the control quantity calculated by the control quantity calculator,
wherein the control quantity calculator performs computation by using the voltage values at the one or more voltage measuring points and the system impedance value to calculate the control quantity which (i) causes a voltage value at a specific voltage measuring point to be substantially equal to the target voltage value, and (ii) when the control quantity calculator determines that voltage values at all voltage measuring points having voltage values deviating from the target voltage value deviate from the target voltage value in a same direction, causes each of the plurality of power regulating apparatuses to output only the positive reactive power or only the negative reactive power, the specific voltage measuring point being included in the voltage measuring points having the voltage values deviating from the target voltage value.

2. The voltage control apparatus according to claim 1 ,
wherein the plurality of power regulating apparatuses are interconnected to the distribution system, and
when the one or more voltage measuring points includes a voltage measuring point having a voltage value deviating from the predetermined voltage range, the control quantity calculator calculates the control quantity for each of the plurality of power regulating apparatuses to assign the value of the reactive power to be output by each of the plurality of power regulating apparatuses according to a line resistance value of the system impedance value.

3. The voltage control apparatus according to claim 1 ,
wherein the plurality of power regulating apparatuses are interconnected to the distribution system, and
when the one or more voltage measuring points includes a voltage measuring point having a voltage value deviating from the predetermined voltage range, the control quantity calculator calculates the control quantity for each of the plurality of power regulating apparatuses to assign the value of the reactive power to be input or output by each of the plurality of power regulating apparatuses according to power loss caused within each of the plurality of power regulating apparatuses when each of the plurality of power regulating apparatuses outputs the reactive power.

4. The voltage control apparatus according to claim 1 ,
wherein the obtainer further obtains the value of the reactive power output by each of the plurality of power regulating apparatuses,
when the one or more voltage measuring points include a voltage measuring point having a voltage value deviating from the predetermined voltage range at current time t, the control quantity calculator compares, with a predetermined value, an absolute value of a difference between (i) the value of the reactive power obtained by the obtainer at the current time t, and (ii) a first reactive power value calculated at time t−1 as the value of the reactive power to be output by each of the plurality of power regulating apparatuses,
when the absolute value of the difference is greater than the predetermined value, the control quantity calculator calculates, as the control quantity, a value of a sum of (i) the value of the reactive power calculated at the current time t, and (ii) the value of the reactive power obtained by the obtainer at the current time t, and
when the predetermined value is greater than the absolute value of the difference, the control quantity calculator calculates, as the control quantity, a value of a sum of (i) the value of the reactive power calculated at the current time t, and (ii) the first reactive power value.

5. The voltage control apparatus according to claim 1 ,
wherein the obtainer further obtains the value of the reactive power output by each of the plurality of power regulating apparatuses,
when the one or more voltage measuring points include a voltage measuring point having a voltage value deviating from the predetermined voltage range at current time t, the control quantity calculator compares, with a predetermined value, an absolute value of a difference between (i) the value of the reactive power obtained by the obtainer at the current time t, and (ii) a first reactive power value calculated at time t−1 as the value of the reactive power to be output by each of the plurality of power regulating apparatuses,
when the absolute value of the difference is greater than the predetermined value, the control quantity calculator calculates the first reactive power value as the control quantity, and
when the predetermined value is greater than the absolute value of the difference, the control quantity calculator calculates, as the control quantity, a value of a sum of (i) the value of the reactive power calculated at the current time t, and (ii) the first reactive power value.

6. The voltage control apparatus according to claim 1 ,
wherein, when the one or more voltage measuring points include a plurality of voltage measuring points having voltage values deviating from the predetermined voltage range, and when all of the voltage values deviating from the predetermined voltage range at the voltage measuring points deviate from the target voltage value in a same direction,
the control quantity calculator (i) identifies, as the specific voltage measuring point, a voltage measuring point having a largest voltage deviation amount among the voltage measuring points having the voltage values deviating from the predetermined voltage range, and (ii) calculates the control quantity, which causes the voltage value at the specific voltage measuring point to be substantially equal to the target voltage value.

7. The voltage control apparatus according to claim 1 ,
wherein, when (i) the one or more voltage measuring points include a plurality of voltage measuring points having voltage values deviating from the predetermined voltage range, (ii) the predetermined voltage range includes a first target voltage value and a second target voltage value that is smaller than or equal to the first target voltage value, and (iii) at least one of the voltage values at the voltage measuring points is above the first target voltage value and at least one of the voltage values at the voltage measuring points is below the second target voltage value,
the control quantity calculator (i) identifies, as a first specific point, a voltage measuring point having a largest voltage deviation amount among the voltage measuring points having the voltage values above the first target voltage val

Assignees

• Panasonic Corp

Inventors

• Watanabe Kenichi
• Kondoh Junji

Classifications

• H02J2105/42

  Home appliances · CPC title

• H02J13/1331

  using wireless data transmission · CPC title

• H02J13/1321

  using a wired telecommunication network or a data transmission bus · CPC title

• H02J13/1311

  using the power network as support for the transmission · CPC title

• H02J13/14

  the power network being locally controlled, e.g. home energy management systems [HEMS] · CPC title