JP2012253851A - Home energy management system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a home energy management system which can avoid rising of power distribution line voltage and be stably available in cooperation with a power distribution system.SOLUTION: A home energy management system comprises: a database 210 which stores user information of a plurality of users; a PV power generation amount model 222 which calculates a power generation amount of a photovoltaic generation device 110 after a predetermined time, on the basis of a power generation amount and specifications of the photovoltaic generation device 110 and weather information; a power demand model 224 which calculates a power demand amount of each user after a predetermined time on the basis of the user information and the weather information; a power distribution system model 230 which calculates power distribution line voltage after a predetermined time on the basis of a reverse flow quantity of each user after a predetermined time in which the reverse flow quantity is obtained by subtracting a calculation result of the power demand model 224 from a calculation result of the PV power generation amount model 222, and the power supply amount and the power distribution line voltage of a power distribution system; and a comparator 240 which compares the power distribution line voltage after a predetermined time with a voltage reference value and outputs a reactive power control request if the power distribution line voltage after a predetermined time exceeds the voltage reference value.

Description

  Embodiments described herein relate generally to a home energy management system.

  As a home energy management system (HEMS: Home Energy Management System) for networking and controlling energy consuming equipment in consumers such as electrical equipment and hot water supply equipment, for example, it converts solar light energy into electrical energy and generates electricity Solar power generators, power conditioners (PCS) that convert DC power generated by solar power generators into AC power for use in customers and to connect to power distribution systems, and power generation by solar power generators A solar power generation system having a display unit that displays the amount, the amount of power sold or the amount of power purchased, and a system controller that controls devices in the solar power generation system in accordance with the state of the solar power generation system Proposed.

  Consumers equipped with solar power generation equipment used the power generated by solar power generation to cover the power consumption in the consumer during the day, and the generated power of the solar power generation equipment exceeded the power consumption, resulting in surplus power. In such a case, it is possible to perform so-called power sale in which surplus power is sent to the distribution system.

JP 2003-224892 A JP 2007-97310 A JP 2007-306744 A JP 2008-35640 A JP 2009-268247 A

  However, when a large amount of distributed power sources such as solar power generators are connected to the distribution system, the distribution line voltage increases due to the reverse power flow, and it is difficult to maintain the distribution line within the specified range. In conventional distribution systems, voltage adjustment by tap switching of SVR (step type automatic voltage regulator) and transformer with load tap switching device, power capacitor, shunt reactor, SVC (static reactive power compensator), STATCOM The distribution line voltage is adjusted to be maintained within a specified range by phase adjusting equipment such as (self-excited reactive power compensator) and reactive power adjustment.

  Only the above-mentioned measures for the distribution system require enormous capital investment and increase the burden on the electric power company. Moreover, since part of the investment recovery of the electric power company is added to the electric power charge, it is not preferable for the customer side.

  On the other hand, in general, a power conditioner that is connected to a power distribution system first supplies a phase advance reactive power when the voltage at the connection point deviates from an appropriate range (for example, 101V + 6V) stipulated by the Electricity Business Law, etc. Still, when the voltage at the power receiving point deviates from the upper limit value and the power factor becomes less than the limit value (for example, 0.85), a function for reducing the active power with the power factor limit value (0.85) is provided. Yes. However, this function can be omitted in a small capacity photovoltaic power generation system.

  However, frequently limiting the output of the active power of the photovoltaic power generation system as described above will lead to a disadvantage for the consumer. Therefore, it is desirable to avoid situations where the output of the active power of the photovoltaic power generation system must be limited.

  In addition, in a customer with a distributed power source and storage battery such as a solar power generation device, when the power flow at the power receiving point from the distribution system is measured, and the power flow at the power receiving point is a reverse power flow exceeding the specified amount In addition, it has also been proposed to charge the storage battery with the power generated by the distributed power source to suppress the reverse power flow to the substation on a customer basis.

  As described above, when the storage battery device is installed on the consumer side, in addition to problems such as cost effectiveness and installation space, the profits obtained for the consumer are not necessarily large, and it is difficult to disseminate them in ordinary households.

  Furthermore, as mentioned above, abnormalities in the distribution system are caused by centralized interconnection of distributed power sources installed in multiple customers. It is desirable to take measures.

  This invention is made in view of the said situation, Comprising: It aims at providing the home energy management system which avoids a raise of a distribution line voltage and can be stably used in connection with a distribution system. .

  According to the embodiment, PV power generation that calculates a power generation amount of a solar power generation device after a predetermined time from a database storing user information of a plurality of consumers, a power generation amount and specifications of the solar power generation device, and weather information Subtracting the calculation result of the power demand model from the calculation result of the PV power generation model, and the power demand model for calculating the power demand amount after the predetermined time in each consumer from the quantity model, the user information and the weather information A distribution system model for calculating the distribution line voltage after the predetermined time from the reverse power flow after the predetermined time of each consumer, the power supply amount and the distribution line voltage of the distribution system, and the distribution after the predetermined time. A comparator that compares the wire voltage with a voltage reference value and outputs a reactive power control request when the distribution line voltage after the predetermined time exceeds the voltage reference value. Theft system is provided.

It is a figure showing roughly an example of 1 composition of a home energy management system of an embodiment. It is a figure showing roughly an example of 1 composition of a cloud computing system of a home energy management system of an embodiment. It is a flowchart for demonstrating an example of operation | movement of the cloud computing system of the home energy management system of embodiment. It is a flowchart for demonstrating an example of operation | movement of the solar energy power generation system of the home energy management system of embodiment. It is a figure which shows roughly the other structural example of the cloud computing system of the home energy management system of embodiment.

Hereinafter, the home energy management system of an embodiment is explained with reference to drawings.
FIG. 1 schematically shows a configuration example of a home energy management system (hereinafter referred to as HEMS) according to the first embodiment. The HEMS of this embodiment includes a cloud computing system 200 that can communicate with the solar power generation systems 100 of a plurality of customers.

  The solar power generation system 100 includes a solar power generation device 110, a power conditioner (PCS) 120, a distribution board 130, a communication terminal 140, and a power measurement unit 150.

  The solar power generation device 110 includes a plurality of solar cells that convert light energy into electric energy, and outputs DC power generated by the plurality of solar cells. The DC power output from the solar power generator 110 is supplied to the power conditioner 120.

  The power conditioner 120 converts the DC power supplied from the solar power generation device 110 into AC power and supplies the AC power to home appliances, hot water supply devices, and the like. The power conditioner 120 can measure the amount of power used by the consumer from the main circuit. The power conditioner 120 has active power and invalidity for power consumed by consumers, power generated by the photovoltaic power generation device, power supplied from the commercial power grid, and power flowing backward to the commercial power grid. A measuring means capable of measuring both power and electric power is provided. The measuring means for measuring reactive power may be a power factor measuring means or a phase measuring means.

  The distribution board 130 supplies power from the commercial power system and the power conditioner 120 to power devices such as home appliances, hot water supply devices, and electric vehicles (EV).

  The power measuring means 150 measures the amount of power supplied from the commercial power system and the amount of power flowing backward to the commercial power system. Note that, like the power conditioner 120, the power measuring means 150 is the power consumed by the consumer, the generated power in the solar power generation apparatus, the power supplied from the commercial power system, and the reverse to the commercial power system. For each power that flows, there may be provided measuring means capable of measuring both active power and reactive power.

  The communication terminal 140 is a mobile communication terminal such as a mobile phone, and communicates with the power conditioner 120 and can communicate with the cloud computing system 200. The communication terminal 140 acquires the amount of power generated by the photovoltaic power generator 110 from the power conditioner 120, acquires the active power and reactive power consumed by the consumer from the power measuring means 150 or the power conditioner 120, and configures the network. To the cloud computing system 200. Further, the communication terminal 140 can receive guidance information and control commands for using electric power equipment owned by a consumer from the cloud computing system 200.

  Note that the power generation amount of the solar power generation device 110 may be transmitted by the power conditioner 120 to the cloud computing system 200 via the network, and when other communication means such as a router device is installed. Other communication means such as a router may directly communicate with the cloud computing system 200 to transmit the amount of generated power of the photovoltaic power generation apparatus 110 and active power and reactive power consumed by consumers via the network. .

  FIG. 2 schematically shows a configuration example of the cloud computing system 200. The cloud computing system 200 includes a database 210, a low-voltage customer model 220, a power distribution system model 230, and a comparator 240.

  The database 210 stores user information for predicting the amount of power consumed by the consumer, such as family structure, statistical information, and past power demand (active power, reactive power) for each consumer.

  The low-pressure consumer model 220 is provided for each of a plurality of consumers. The low-voltage customer model 220 includes a solar power generation model (hereinafter referred to as a PV power generation model) 222 and a power demand model 224. The PV power generation amount model 222 is a model for predicting the power generation amount of the solar power generation device 110 after a predetermined time based on the specifications of the solar power generation device 110, weather information, user information, and the like. The power demand model 224 is a model for predicting the power demand after a predetermined time at each consumer.

  The distribution system model 230 includes a distribution line model 232 and a distribution device model 234. The distribution line model 232 is for predicting the distribution line voltage at the interconnection point after a predetermined time from the reverse power flow after a predetermined time calculated by the low-voltage customer model 220 and the power system information from the power system monitoring and control system. It is a model. The distribution device model 234 is a model of a device installed in a distribution system such as a transformer.

  Distribution line voltage rises due to reverse power flow from multiple customers connected to the same distribution system. Distribution system such as voltage rise of distribution line based on information from one customer's photovoltaic power generation system. It is difficult to grasp the state of Therefore, in the present embodiment, as described above, information such as generated power is collected from the solar power generation systems of a plurality of customers linked to the same distribution system, and a tendency of voltage increase of the distribution line is detected. Is possible.

  Furthermore, in the present embodiment, the cloud computing system 200 is configured so that the reactive power consumed by the consumers is communicated via the communication terminals 140 of a plurality of customers linked to the local power distribution system or other communication means. A reactive power consideration calculation unit 260 that collects data related to the amount and calculates the value of money, gift certificates, and other incentives is provided.

  Usually, the power charge is charged for the active power consumed by the consumer, and the reactive power is not excluded as a metered charge. However, since the reactive power contributes to the stabilization of the distribution line voltage as described above, in this embodiment, the reactive power value calculation unit 260 calculates the value of the reactive power, and the consumer and the power company When it falls below the power factor standard of the contracted extra charge, it is possible to compensate the disadvantage of the consumer based on the value of reactive power calculated previously. Note that incentives may be given to reactive power supply even if there is no power factor decrease that leads to an extra charge.

  Furthermore, application software necessary for the reactive power control function may be downloaded from the cloud computing system 200 to the customer communication terminal 140. As described above, when an application of the home energy management system can be operated on a general-purpose information terminal having a communication function such as a mobile phone or a smartphone, or a home appliance such as a personal computer or a television receiver, the consumer can use the home energy of the present embodiment. There is no need to install a communication terminal dedicated to the management system.

  FIG. 3 shows a flowchart for explaining an example of the operation of the cloud computing system of the home energy management system of the present embodiment.

  First, the cloud computing system 200 receives the generated power of the solar power generation device 110 from the solar power generation system 100 installed in a plurality of customers in a predetermined area (step STA1). The received generated power is supplied to the PV power generation model of the low-voltage customer model 220 of each customer.

Subsequently, a predicted value of the distribution line voltage is calculated (step STA2).
The PV power generation amount model 222 includes weather information such as calendar, time zone, weather, temperature, and solar radiation supplied from the weather information service via the network, and rated power generation supplied from the solar power generation system 100 via the network. The amount of power generation after a predetermined time of the solar power generation device 110 from the specification information of the solar power generation device 110 such as the amount, and the amount of solar power generation supplied from the solar power generation system 100 of another customer via the network Is calculated.

  The power demand model 224 includes weather information such as a calendar, time zone, weather, temperature, and solar radiation supplied from the weather information service via the network, a family structure of consumers supplied from the database 210, and past power demand. The power demand after a predetermined time of the consumer is calculated from statistical information such as average and variance of the quantity and user information such as past power demand. The past power demand supplied from the database 210 includes the demand for active power and the demand for reactive power.

  The subtractor 226 subtracts the power demand output from the power demand model 224 from the power generation amount of the photovoltaic power generation apparatus 110 output from the PV power generation amount model 222 and outputs a surplus power amount. The surplus power amount output from the subtractor 226 is the reverse power flow from each customer to the distribution line.

  The distribution system model 230 includes the distribution line model 232 and the distribution power model supplied from the power system monitoring and control system, the distribution line voltage measured at various points, and the reverse power flow to the distribution line. Using the distribution device model 234 such as a transformer, the predicted value of the distribution line voltage at the interconnection point of the consumer is calculated. The predicted value of the distribution line voltage output from the distribution system model 230 is input to the comparator 240.

Subsequently, it is determined whether or not the distribution line voltage exceeds the voltage reference value (step STA3).
That is, the comparator 240 compares the predicted value of the distribution line voltage input from the distribution system model 230 with the voltage reference value. If the predicted value of the distribution line voltage exceeds the voltage reference value, the comparator 240 requests the reactive power control. Output (step STA4). When the predicted value of the distribution line voltage is equal to or lower than the voltage reference value, the generated power of the photovoltaic power generator 110 is received again and the above operation is performed. Here, in this embodiment, the voltage reference value adopted by the comparator 240 is 107 V, which is the upper limit reference value of the appropriate range of the distribution line voltage stipulated by the Electricity Business Law or the like.

  In FIG. 4, the flowchart for demonstrating an example of operation | movement of the solar energy power generation system of the home energy management system of this embodiment is shown. When the photovoltaic power generation system 100 receives the reactive power control request from the cloud computing system 200 at the communication terminal 140 (step STB1), the photovoltaic power generation system 100 supplies the reactive power control request to the power conditioner 120.

  The power conditioner 120 confirms the power supply agreement between the power company and the customer, sets a predetermined power factor lower limit value in the power conditioner 120, and controls so as not to fall below the power factor lower limit value. It is determined whether or not it is being performed (step STB2).

  Here, the power conditioner 120 of the photovoltaic power generation system 100 connected to the power distribution system first proceeds when the voltage at the connection point deviates from an appropriate range (for example, 101V + 6V) defined by the Electricity Business Law. When the phase reactive power is supplied to lower the voltage at the interconnection point, and the voltage at the interconnection point still deviates from the upper limit value and the power factor becomes less than the lower limit value (for example, 0.85), the power factor lower limit value There is a case where a function for reducing the active power is provided as it is (0.85).

  In general, it is desirable that the power factor is close to 1 in an electric power system. If the power factor lower limit value is exceeded, the power supply contract between the power company and the customer is based on the power supply agreement.If the power factor lower limit value is exceeded, the customer receives a discount on the fee. In some cases, an extra fee may be paid. In this case, the power conditioner 120 is operated so as not to fall below the lower limit value of the power factor, and it is possible to avoid paying an extra charge.

  Therefore, in this embodiment, when the power factor lower limit value is set in the power conditioner 120, the power factor lower limit value set in the power conditioner 120 is corrected to a lower value (step STB3) and further progressed. It is possible to supply phase reactive power.

  As described above, in the present embodiment, when the cloud computing system 200 predicts that the distribution line voltage at the interconnection point exceeds the allowable value, the reactive power control request is sent to the consumer's solar power generation system 100. When the solar power generation system 100 receives the request and the predetermined power factor lower limit value is set in the power conditioner 120, the power factor lower limit value of the power conditioner 120 is set to a lower value. The phase advance reactive power can be supplied after correction.

  The cloud computing system 200 may cancel the reactive power control request when the predicted value of the distribution line voltage becomes equal to or lower than the voltage reference value. When the reactive power control request is canceled, the power conditioner 120 of the photovoltaic power generation system 100 returns the power factor lower limit value to the value before correction.

  As described above, when the power factor falls below the power factor lower limit value, the power factor lower limit value is corrected to a lower value and the reactive power can be supplied. Since the opportunity to limit the output of active power due to is reduced, it becomes possible to continue selling the surplus power by that amount, and it is possible to obtain more income from the sale of power.

  In addition, if the customer has a contract to pay an extra charge with the power company when the power factor falls below the lower limit of the power factor, the customer pays the power company by profits or incentives from power sales. The user's burden can be reduced by offsetting the extra charge.

  Since the power supplier suppresses the voltage increase of the distribution line, the power company does not need to invest in equipment installed in the distribution system to maintain the voltage. As a result, it is possible to avoid an increase in power charges.

  That is, according to the home energy management system of the present embodiment, it is possible to provide a home energy management system that can avoid the increase of the distribution line voltage and can be stably used in connection with the distribution system.

  Next, a home energy management system according to a second embodiment will be described with reference to the drawings. In the following description, the same components as those in the first embodiment described above are denoted by the same reference numerals and description thereof is omitted.

  In the present embodiment, the consumer group that can communicate with the cloud computing system 200 includes a consumer having the phase adjusting equipment 300 such as a power capacitor and a reactor. For example, this applies to low-voltage customers such as town factories, shops, and small and medium buildings. These consumers do not necessarily have the solar power generation system 100.

  In the present embodiment, the cloud computing system 200 collects and collects the amount of power generated by the photovoltaic power generation apparatus 110 via a communication terminal 140 of a customer linked to a local power distribution system and other communication means. The predicted value of the distribution line voltage of the distribution system is calculated from the generated power amount.

  When the predicted value of the distribution line voltage exceeds the voltage reference value, the cloud computing system 200, in addition to the consumer having the photovoltaic power generation system 100, the consumer having the phase adjusting equipment linked to the same distribution system Is requested to operate the phase adjusting equipment 300 by outputting a reactive power control request.

  When the customer having the phase adjusting equipment 300 receives the reactive power control request, the customer disconnects the power capacitor and enters a reactor. In this way, by operating the phase adjusting equipment 300, reactive power can be consumed or supplied, and the voltage of the interconnected distribution system can be further reduced.

  In this embodiment, the reactive power consideration calculation unit 260 of the cloud computing system 200 collects data related to the amount of reactive power of a consumer having a phase adjusting facility 300 linked to a local power distribution system, Calculate the value of tickets and other incentives.

  When the value of the reactive power is calculated as described above and the customer having the phase adjusting equipment 300 falls below the power factor standard of the extra charge contracted with the electric power provider, the cloud computing system 200 calculates first. Based on the value of reactive power, it is possible to provide an incentive that sufficiently offsets the disadvantage of consumers due to consumption of reactive power. In addition, even if there is no power factor decrease that leads to an extra charge, an incentive for reactive power supply may be given.

  As described above, according to the home energy management system of the present embodiment, the same effects as those of the first embodiment described above can be obtained, and it is required that the customer having the phase adjusting equipment 300 operates the phase adjusting equipment. By doing so, it becomes possible to more effectively avoid an increase in the distribution line voltage. In addition, a consumer having the phase adjusting equipment 300 can receive incentives such as money for operating the phase adjusting equipment 300 and consuming reactive power.

  In addition, especially when the IH cooking heater is included in the electric power equipment owned by the consumer, it is possible to use the coil in the IH cooking heater. An IH cooking heater is a device in which an alternating current of tens of kHz generated by an inverter is passed through an internal coil, and Joule heat is generated by an induced current on the bottom surface of a pot placed on a stove and heated. It has a large capacity among kW and power equipment installed in houses.

  When the predicted value of the distribution line voltage exceeds the voltage reference value, the cloud computing system 200 outputs a reactive power control request to a consumer having an IH cooking heater and requests a reactive power supply.

  A normal IH cooking heater is provided with a power factor correction circuit that brings the power factor close to 1, but when accepting a request for reactive power supply, a consumer turns off the power factor correction circuit and uses the IH cooking heater. This supplies reactive power to the distribution system.

  In this case, the cloud computing system 200 gives the customer an incentive for the reactive power supplied by the IH cooking heater, as in the case of the first and second embodiments described above.

  Thus, the reactive power consumed by the IH cooking heater can be effectively used to avoid an increase in the distribution line voltage.

  Although several embodiments of the present invention have been described, these embodiments are presented by way of example and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the scope of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalents thereof.

  For example, although the home energy management system of the above-described embodiments includes the cloud computing system 200, the cloud computing system 200 and the server are installed using a server device or database installed in an area connected to the power distribution system. A similar configuration may be realized. Even in such a case, the same effects as those of the plurality of embodiments can be obtained.

  DESCRIPTION OF SYMBOLS 100 ... Solar power generation system, 110 ... Solar power generation device, 120 ... Power conditioner (PCS), 130 ... Distribution board, 140 ... Communication terminal, 150 ... Electric power measurement means, 200 ... Cloud computing system, 210 ... Database 220 ... Low-voltage customer model, 222 ... Solar power generation model (PV power generation model), 224 ... Power demand model, 230 ... Distribution system model, 232 ... Distribution line model, 234 ... Distribution equipment model, 240 ... Comparator, 260: Reactive power consideration calculation unit, 300: Phase adjusting equipment.

Claims (4)

A database storing user information of multiple consumers;
PV power generation model for calculating the power generation amount and specifications of the solar power generation device and the power generation amount of the solar power generation device after a predetermined time from the weather information,
A power demand model that calculates the power demand after the predetermined time in each consumer from the user information and weather information;
After the predetermined time from the reverse power flow after the predetermined time of each consumer obtained by subtracting the calculation result of the power demand model from the calculation result of the PV power generation amount model, and the power supply amount and distribution line voltage of the distribution system A distribution system model that calculates the distribution line voltage of
A comparator that compares the distribution line voltage after the predetermined time with a voltage reference value and outputs a reactive power control request when the distribution line voltage after the predetermined time exceeds the voltage reference value. Management system. A solar power generation device for supplying generated power to the consumer;
Measuring means for measuring active power and reactive power consumed in the consumer;
The power factor lower limit value of the power factor of the power consumed in the consumer is set, and a power conditioner that converts the DC power output from the photovoltaic power generator into AC power,
A communication unit that outputs the active power and reactive power measured by the measuring unit and receives the reactive power control request,
The home energy management system according to claim 1, wherein the power conditioner corrects the power factor lower limit value to be low when the reactive power control request is received via the communication unit.   The home energy management system according to claim 1, further comprising a reactive power consideration calculating unit that receives the reactive power consumed by the consumer, calculates a value of the reactive power, and outputs the value. The comparator is a home energy management system that outputs the reactive power control request having phase adjusting equipment to a consumer,
The home energy management system according to claim 1, further comprising a reactive power consideration calculation unit that receives a reactive power amount consumed by a consumer having the phase adjusting equipment, calculates a value of the reactive power amount, and outputs the value.

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