JP5731913B2 - Storage battery charge / discharge control device, power control system, and storage battery charge / discharge control method - Google Patents

Description

  The present invention relates to charge / discharge control of a storage battery, and more particularly to a storage battery charge / discharge control device, a power control system, and a storage battery charge / discharge control method.

  In recent years, power sales to the power system by distributed power sources such as solar power generation devices are increasing, and the reverse power flow from the distributed power source to the power system becomes impossible due to the increase of the system voltage by the distributed power source. There is a problem that power is wasted. Although the system voltage is set to 101 ± 6V by the Electric Power Business Law, the voltage received by low-voltage consumers is likely to deviate from the upper limit of 107V when the reverse power flow by the distributed power source increases. As a voltage rise suppression measure, when the system voltage exceeds the upper limit (107V), the power factor of the reverse power flow by the distributed power source is set to the phase advance power factor to suppress the rise of the system voltage. However, when the power factor of reverse power flow exceeds the limit value, reverse power flow is not possible. In particular, in the case of photovoltaic power generation, there is a high possibility that the timing of reverse power flow by each distributed power source will coincide. For this reason, each consumer is equipped with a storage battery, and it leads to the rise suppression measure of a system voltage by distributing the timing of a reverse power flow, and generation | occurrence | production of surplus electric power can be suppressed.

  The following Patent Document 1 discloses a configuration in which system voltage is detected, and when the system voltage is rising, the generated power of solar power generation is stored in a storage battery. By introducing such a storage battery into each distributed power source, the timing of reverse power flow from each distributed power source to the power system can be shifted, and it is possible to maintain the quality of the power system and suppress the generation of surplus power.

JP 2004-180467 A

  However, in order to charge the storage battery with the generated power of the distributed power source, it is necessary to discharge the storage battery to some extent in advance. In the invention of Patent Document 1, charge / discharge control of the storage battery is performed while predicting an increase in system voltage. The configuration to be performed is not described.

  In addition, at present, it is difficult to install a storage battery in a general household equipped with a solar power generation device, but since communication equipment has a storage battery, the storage battery can be used effectively, It is considered effective to charge the surplus power of the distributed power source. However, since storage batteries for communication facilities are always available for power outages, they are normally operated in a fully charged state and have almost no chance of discharging.

  The present invention has been made to solve the above-described problem. By discharging and charging the storage battery at an appropriate timing, it is possible to charge the surplus power of the distributed power supply while suppressing the voltage increase of the system voltage. For the purpose.

A storage battery charge / discharge control device according to the present invention includes an AC / DC converter that rectifies AC power input from a power system into DC power and outputs the rectified DC power to a load, a storage battery, and a system of the power system. A system voltage detecting means for detecting and recording a voltage; a system voltage threshold value exceeding time that is a time when the system voltage next exceeds a predetermined threshold from the system voltage recorded by the system voltage detecting means; and A system voltage predicting means for predicting a next system voltage threshold excess time that is a length of a period during which the system voltage exceeds the threshold from the next system voltage threshold exceeding time, and a next predicted by the system voltage predicting means Charge / discharge control for controlling discharge from the storage battery to the load and charge from the power system to the storage battery based on a system voltage threshold excess time and a next system voltage threshold excess time And means, wherein the charge and discharge control means, the next system voltage time traced back by the next system voltage threshold over time from the threshold excess time or from time going back by the next system voltage threshold over time more time predated predetermined time, to connect the battery to the load you start discharging to the load from the battery.

  In the storage battery charge / discharge control device, the system voltage detecting means detects and records the system voltage of the power system, and the system voltage predicting means predetermines the system voltage from the system voltage recorded by the system voltage detecting means. “Next grid voltage threshold excess time”, which is the time when the next grid voltage threshold is exceeded, and “next grid,” which is the length of the period when the grid voltage exceeds the threshold from the next grid voltage threshold excess time Predict "voltage threshold exceeded time". Then, the charge / discharge control means controls the discharge from the storage battery to the load and the charging from the power system to the storage battery based on the predicted “next system voltage threshold excess time” and “next system voltage threshold excess time”. To do.

  Further, the system voltage predicting means may predict the next system voltage threshold excess time and the next system voltage threshold excess time from the system voltage threshold excess time, system voltage threshold excess time, day of week information, etc. recorded in the past. Good.

  The invention related to the storage battery charge / discharge control apparatus as described above is an invention related to a power control system including an electric power system, a storage battery charge / discharge control apparatus, and a load, and a storage battery executed by the storage battery charge / discharge control apparatus. It can be understood as an invention relating to a charge / discharge control method, and can be described as follows. The invention relating to the following power control system and the invention relating to the storage battery charge / discharge control method also exhibit the same operations and effects as the invention relating to the storage battery charge / discharge control device.

The power control system according to the present invention is a power control system configured to include a power system, a storage battery charge / discharge control device, and a load, and the storage battery charge / discharge control device is an AC power input from the power system. An AC / DC converter that outputs the rectified DC power to the load, a storage battery, a system voltage detection unit that detects and records a system voltage of the power system, and a system voltage detection unit From the recorded grid voltage, the next grid voltage threshold excess time, which is the time when the grid voltage next exceeds a predetermined threshold, and the grid voltage exceeds the threshold from the next grid voltage threshold excess time A system voltage prediction means for predicting a next system voltage threshold excess time which is the length of the period, a next system voltage threshold excess time predicted by the system voltage prediction means and a next system power Based on the threshold over time, a charge and discharge control means for controlling the charging from the battery to the battery from the discharge and the electric power system to the load, wherein the charge and discharge control means, the next system voltage threshold The storage battery is connected to the load at a time that is traced back by the next grid voltage threshold excess time from an excess time, or a time that is traced back by a predetermined time from the time traced by the next grid voltage threshold excess time. start a discharge to the load from the battery.

A storage battery charge / discharge control method according to the present invention includes: an AC / DC converter that rectifies AC power input from a power system into DC power and outputs rectified DC power to a load; and a storage battery. A storage battery charge / discharge control method executed by an apparatus, wherein a system voltage is detected in advance from a system voltage detection step for detecting and recording a system voltage of the power system, and a system voltage recorded in the system voltage detection step. The next grid voltage threshold excess time that is the next time that exceeds the predetermined threshold, and the next grid voltage threshold that is the length of the period during which the grid voltage exceeds the threshold from the next grid voltage threshold excess time Based on the system voltage prediction step for predicting the excess time, the next system voltage threshold excess time and the next system voltage threshold excess time predicted in the system voltage prediction step, A discharge control step of controlling the charging of the battery from the discharge and the electric power system to the load from the serial accumulator, wherein the at charge and discharge control step, the next line from the next of the system voltage threshold exceeded time Discharge from the storage battery to the load by connecting the storage battery to the load at a time that is back by the voltage threshold excess time, or a time that is a predetermined time further from the time that is back by the next grid voltage threshold excess time start the.

  ADVANTAGE OF THE INVENTION According to this invention, the surplus electric power of a distributed power supply can be charged, suppressing the voltage rise of a system voltage by discharging and charging a storage battery at appropriate timing. For example, when the power system voltage rises due to the power generation of the distributed power source and surplus power is generated, for example, the storage battery in the communication facility can be charged with surplus power, and the distributed power source such as a solar power generation device cannot generate power The situation can be suppressed, and the power of the distributed power source can be used effectively.

1 is a functional block diagram of a power control system according to an embodiment of the invention. It is a figure which shows an example of the time-sequential change of a system voltage. It is a flowchart which shows the processing content performed by the storage battery charging / discharging control apparatus. It is a figure which shows an example of the hardware constitutions of a storage battery charging / discharging control apparatus.

  Embodiments according to the present invention will be described below with reference to the drawings.

  In FIG. 1, the functional block diagram of the electric power control system 1 containing the storage battery charging / discharging control apparatus 10 is shown. As shown in FIG. 1, the power control system 1 includes a power system 30, a storage battery charge / discharge control device 10, and a DC load 20. Among these, the storage battery charge / discharge control device 10 includes a storage battery 11, an AC / DC converter (rectifier) 12, a charge / discharge control unit 13, a system voltage prediction unit 14, and a system voltage detection unit 15.

  Among these, the AC / DC converter 12 rectifies AC power input from the power system 30 into DC power, and outputs the DC power after rectification to the storage battery 11 or the DC load 20.

  The system voltage detection means 15 detects the system voltage of the power system 30 and records the detection result in a built-in memory (not shown). That is, since the change in the voltage value of the power system 30 varies depending on each distribution network, the system voltage detection unit 15 records the detection result of the system voltage in time series in the built-in memory.

  The system voltage predicting unit 14 reads the time-series system voltage detection result recorded by the system voltage detecting unit 15, and from the obtained time-series system voltage detection result, the system voltage is set to a predetermined threshold value. “Next system voltage threshold excess time T”, which is the time when the next system voltage is exceeded, and “next system voltage, which is the length of the period when the system voltage exceeds the above threshold from the next system voltage threshold excess time” The threshold excess time T3 ”is predicted.

  Based on the “next system voltage threshold value excess time T” and the “next system voltage threshold value excess time T3” predicted by the system voltage prediction unit 14, the charge / discharge control unit 13 performs, for example, a process described later from the storage battery 11. It controls the discharge to the DC load 20 and the charging from the power system 30 to the storage battery 11. Details of the control will be described later with reference to FIG.

  In FIG. 4, an example of the hardware constitutions of the storage battery charging / discharging control apparatus 10 is shown. The storage battery charge / discharge control device 10 includes, as a hardware configuration, a CPU 10A, a RAM 10B, a ROM 10C, an input unit 10D such as a keyboard and a mouse that are input devices, a communication unit 10E that communicates with an external device, and an auxiliary storage. Unit 10F and an output unit 10G such as a display or a printer as an output device. The function of each functional block of the storage battery charging / discharging control device 10 described above causes the RAM 10B and the like to read a predetermined program and operate the input unit 10D, the communication unit 10E, and the output unit 10G under the control of the CPU 10A, and the auxiliary storage unit This is realized by reading / writing data from / to 10F.

  By the way, the storage battery charging / discharging control apparatus 10 may be provided in distributed power supplies, such as a solar power generation device, for example, and may be provided in communication equipment. If the storage battery charging / discharging control device 10 is provided in a distributed power source such as a solar power generation device, the AC / DC converter 12 is configured by configuring the AC / DC converter 12 with a bidirectional inverter. It is desirable that the solar power generation unit (solar cell) connected to the power system 30 through the backflow prevention diode be configured to allow backflow to the power system 30.

  Now, FIG. 2 shows an example of the time series change of the system voltage. When there are many distributed power sources such as photovoltaic power generation devices, the system voltage rises during the daytime, so the system voltage threshold excess time T is during the daytime and often has periodic characteristics. As shown in FIG. 2, the system voltage threshold is set to 106 V, for example, and the system voltage predicting unit 14 determines that the system voltage is the threshold (from the time-series system voltage detection result recorded by the system voltage detecting unit 15. 106V) exceeding the system voltage threshold time and the length of the period when the system voltage exceeds the threshold (106V) from the system voltage threshold excess time (system voltage threshold excess time). Records in a built-in memory (not shown). Then, the system voltage predicting unit 14 predicts the next system voltage threshold excess time and the next system voltage threshold excess time based on the characteristics of such time series change of the system voltage.

  For example, the system voltage predicting means 14 calculates the next system voltage threshold excess time by averaging the past several system voltage threshold excess times, and averages the past several system voltage threshold excess times to obtain the next The grid voltage threshold excess time may be calculated.

  The charge / discharge control means 13 reads the prediction results (the next system voltage threshold excess time T and the next system voltage threshold excess time T3) recorded by the system voltage prediction means 14 and reads “next system voltage threshold excess time T”. From the storage battery 11 by connecting the storage battery 11 to the DC load 20 as advance preparation so that the storage battery 11 can be charged only for a period corresponding to the “next system voltage threshold excess time T3”. Discharge. For example, the charging / discharging control means 13 connects the storage battery 11 to the DC load 20 at a time (T−T3) that is back by “next system voltage threshold excess time T3” from the predicted “next system voltage threshold excess time T”. To start the discharge from the storage battery 11 to the DC load 20. As another example, the charging / discharging control means 13 has a time slightly earlier than the above time (T-T3) (that is, a time further back by a predetermined time than the time (T-T3)) so as to have a margin. Alternatively, the storage battery 11 may be connected to the DC load 20 to start discharging from the storage battery 11 to the DC load 20.

  After such advance preparation (discharge from the storage battery 11 to the DC load 20), the charge / discharge control means 13 charges the storage battery 11 with power from the power system 30 when the system voltage exceeds the system voltage threshold. To control.

  Next, the processing content executed by the storage battery charge / discharge control device will be described with reference to FIG. As a premise of the processing of FIG. 3, the system voltage detection unit 15 detects and records the system voltage of the power system 30, and the system voltage prediction unit 14 determines the time-series system voltage recorded by the system voltage detection unit 15. From the detection result, the system voltage threshold excess time when the system voltage exceeds the threshold (here 106V as shown in FIG. 2), and the length of the period when the system voltage exceeds the threshold (106V) from the system voltage threshold excess time Suppose that (system voltage threshold value excess time) is obtained and the obtained result is recorded in the built-in memory.

  First, at a predetermined time of each day (for example, midnight), the system voltage prediction means 14 predicts the next system voltage threshold excess time T and the next system voltage threshold excess time T3 (step S1 in FIG. 3). . Here, for example, the system voltage predicting means 14 calculates the next system voltage threshold excess time by averaging the past several system voltage threshold excess times, and averages the past several system voltage threshold excess times. The next grid voltage threshold excess time may be calculated. That is, as shown in FIG. 2, the next system voltage threshold excess time T3 may be calculated by averaging the system voltage threshold excess times T1 and T2 for the past two times.

  After that, the system waits until the current time reaches a time (T-T3) that is back from the next grid voltage threshold excess time T by the next grid voltage threshold excess time T3 (steps S2, S3), and the current time is the time (T -T3) (Yes in step S3), the charge / discharge control means 13 connects the storage battery 11 to the DC load 20 and starts discharging from the storage battery 11 to the DC load 20 (step S4). At this time, as another example, the charging / discharging control means 13 is a little earlier than the above time (T-T3) (ie, a time that is further back by a predetermined time from the time (T-T3)) in order to provide a margin. Alternatively, the storage battery 11 may be connected to the DC load 20 to start discharging from the storage battery 11 to the DC load 20.

  Thereafter, the charge / discharge control means 13 monitors whether or not the system voltage detected by the system voltage detection means 15 exceeds the system voltage threshold (106 V) (steps S5 and S6). Then, when the system voltage exceeds the system voltage threshold (106 V) (positive determination in step S6), the charge / discharge control means 13 controls to charge the storage battery 11 with the power from the power system 30 (steps S7, S8). ). The DC load 20 is also controlled so that power is supplied from the power system 30.

  And if the charge to the storage battery 11 is completed (Yes determination at step S8), the process of FIG. 3 will be complete | finished. Although not shown in FIG. 3, the charge / discharge control means 13 monitors the system voltage during charging of the storage battery 11, and if the system voltage is too low, the charge / discharge control means 13 terminates the charging without waiting for the completion of charging. Is preferable.

  According to the embodiment of the invention described above, the surplus power of the distributed power supply can be charged while suppressing the voltage increase of the system voltage by discharging and charging the storage battery at an appropriate timing. For example, when the power system voltage rises due to the power generation of the distributed power source and surplus power is generated, the surplus power can be charged in the storage battery of the communication facility, and the situation where the distributed power source such as the solar power generation device cannot generate power The power of the distributed power source can be effectively used.

  DESCRIPTION OF SYMBOLS 1 ... Electric power control system, 10 ... Storage battery charge / discharge control apparatus, 10A ... CPU, 10B ... RAM, 10C ... ROM, 10D ... Input part, 10E ... Communication part, 10F ... Auxiliary storage part, 10G ... Output part, 11 ... Storage battery , 12 ... AC / DC converter, 13 ... charge / discharge control means, 14 ... system voltage prediction means, 15 ... system voltage detection means, 20 ... DC load, 30 ... power system.

Claims (3)

An AC / DC converter that rectifies AC power input from the power system into DC power and outputs the rectified DC power to a load;
A storage battery,
System voltage detection means for detecting and recording the system voltage of the power system;
From the system voltage recorded by the system voltage detection means, the next system voltage threshold exceeding time, which is the time when the system voltage next exceeds a predetermined threshold, and the system voltage from the next system voltage threshold exceeding time System voltage prediction means for predicting the next system voltage threshold excess time that is the length of the period exceeding the threshold;
A charge for controlling the discharge from the storage battery to the load and the charging from the power system to the storage battery based on the next system voltage threshold excess time and the next system voltage threshold excess time predicted by the system voltage prediction means. Discharge control means;
Equipped with a,
The charge / discharge control means includes
The storage battery is stored at a time that is traced back by the next grid voltage threshold excess time from the next grid voltage threshold exceeded time, or a time that is further traced back by a predetermined time from the time traced by the next grid voltage threshold excess time. A storage battery charge / discharge control device connected to a load and starting discharge from the storage battery to the load . An electric power control system including an electric power system, a storage battery charge / discharge control device, and a load,
The storage battery charge / discharge control device comprises:
AC / DC converter that rectifies AC power input from the power system into DC power and outputs the DC power after rectification to the load;
A storage battery,
System voltage detection means for detecting and recording the system voltage of the power system;
From the system voltage recorded by the system voltage detection means, the next system voltage threshold exceeding time, which is the time when the system voltage next exceeds a predetermined threshold, and the system voltage from the next system voltage threshold exceeding time System voltage prediction means for predicting the next system voltage threshold excess time that is the length of the period exceeding the threshold;
A charge for controlling the discharge from the storage battery to the load and the charging from the power system to the storage battery based on the next system voltage threshold excess time and the next system voltage threshold excess time predicted by the system voltage prediction means. Discharge control means;
Equipped with a,
The charge / discharge control means includes
The storage battery is stored at a time that is traced back by the next grid voltage threshold excess time from the next grid voltage threshold exceeded time, or a time that is further traced back by a predetermined time from the time traced by the next grid voltage threshold excess time. you start discharging to the load from the battery connected to a load,
A power control system characterized by that. A storage battery charge / discharge control method executed by an AC / DC converter that rectifies AC power input from the power system into DC power and outputs the rectified DC power to a load, and a storage battery. Because
A system voltage detection step of detecting and recording a system voltage of the power system;
From the system voltage recorded in the system voltage detection step, the next system voltage threshold excess time, which is the time when the system voltage next exceeds a predetermined threshold, and the system voltage from the next system voltage threshold excess time A system voltage prediction step for predicting the next system voltage threshold excess time, which is the length of the period during which the threshold is exceeded,
Based on the next system voltage threshold exceeded time and the next system voltage threshold exceeded time predicted in the system voltage prediction step, the discharging from the storage battery to the load and the charging from the power system to the storage battery are controlled. A charge / discharge control step;
Equipped with a,
In the charge / discharge control step,
The storage battery is stored at a time that is traced back by the next grid voltage threshold excess time from the next grid voltage threshold exceeded time, or a time that is further traced back by a predetermined time from the time traced by the next grid voltage threshold excess time. A storage battery charge / discharge control method for connecting to a load and starting discharging from the storage battery to the load .

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