JP5900889B2 - Self-sustaining operation system and method for distributed power supply - Google Patents

Description

  The present invention relates to a self-sustaining operation system and method for a distributed power source (microgrid).

  In recent years, efforts to “microgrid” to reduce the burden on the commercial system by load following operation of distributed power sources have become active. In an energy supply system (hereinafter simply referred to as a microgrid) that incorporates the idea of a microgrid, the power generation amount is controlled so that the amount of power purchased from a commercial system is constant by grid interconnection. There is a need for load following operation that performs system operation and performs self-sustained operation that supplies high-quality power (with small fluctuations in voltage and frequency) in the microgrid system in the event of an emergency such as a power failure.

Considering the convenience of power supply in the building, it is possible to construct a system that makes the transition from grid-operated operation to self-sustained operation in an emergency such as a power outage without interruption without maintaining high-quality power supply. desirable.
This allows the continuation of the building without any influence from external power interruptions in the microgrid system, including devices that are relatively sensitive to power quality (voltage and frequency fluctuations) such as computers. Operation becomes possible.

In recent years, natural energy such as solar power generation and wind power generation has been actively used in various fields for the purpose of CO ₂ reduction. For example, as a method of effectively using photovoltaic power generation in the above-described microgrid, in an emergency such as a peak cut operation that is normally linked to a power supply of a commercial system and a power failure of the commercial system, the BCP ( It can be used as a power source for Business Continuity Plan (business continuity plan).

However, in the natural energy power generation using natural energy such as sunlight and wind power, the generated power greatly fluctuates due to changes in the weather and the environment.
For this reason, in order to perform reliable peak cut during the linked operation that operates in conjunction with the power supply of the commercial system, the output of the storage battery (battery) 130 is adjusted according to the fluctuation, and the storage battery is charged and discharged. Need to control. For example, Patent Literature 1 or Patent Literature 2 discloses a system that suppresses or stops the storage battery 130 when the storage battery is fully charged during the self-sustaining operation.

JP 2000-1161010 A JP-A-10-23673

A configuration example of a conventional microgrid will be described with reference to FIG. FIG. 5 is a diagram showing a conventional example of a system configuration for performing uninterrupted power supply when a power failure occurs during commercial interconnection operation.
In the power supply system 90 shown in FIG. 5, during the interconnection operation with the commercial system 200, the first circuit breaker 191 and the ACSW (AC semiconductor switch) 120 are turned on, and the second circuit breaker 192 is opened. . In addition, by performing output control of the storage battery 130 via the INV 135 according to fluctuations in photovoltaic power generation and power load, peak cut operation is performed, and the important load 150, the safety load 160, the disaster prevention load 170, and the general load 180 are changed. In contrast, power is supplied.

  On the other hand, the voltage detection part 181 detects the voltage of the receiving point P1, and opens the 1st circuit breaker 191 and the receiving point circuit breaker 201 at the time of a power failure. Further, the emergency generator 190 starts to be started by a state signal indicating that the first circuit breaker 191 is opened, the ACSW 120 detects the voltage drop and opens, and the self-supporting range (A) due to uninterrupted interruption with respect to an important load. Supply power to the inside. After the emergency generator 190 is started, the control unit 902 is within the range of the self-supporting range (B) by turning on the second circuit breaker 192 and the ACSW 120 and using the solar power generation output by the solar cell 140. Perform autonomous operation.

In addition, when the power of the emergency generator 190 is depleted due to prolonged power failure in the commercial system, the autonomous operation in the autonomous range (A) is continued as long as the remaining amount of the storage battery 130 continues.
When the storage battery 130 is fully charged in a state where the power value of the important load is less than the generated power of the solar battery, a PCS (Power Conditioning System) 901 is stopped due to the DC overvoltage of the storage battery 130. By stopping the PCS 901, power is not supplied to the important load 150, and the important load 150 is interrupted.

For this reason, when the storage battery 130 is fully charged, the control unit 902 stops charging the storage battery 130 from the solar battery 140 as in Patent Documents 1 and 2.
However, after the storage battery 130 becomes fully charged and stops charging, when the charging voltage of the storage battery 130 decreases with respect to the fully charged voltage, charging of the storage battery 130 is resumed.
For this reason, the PCS 601 frequently cuts off the connection between the storage battery 130 and the solar battery 140, and the mechanical operating portion of the PCS deteriorates.

  The present invention has been made in view of such circumstances, and when the generated power of the solar battery is large with respect to an important load during the independent operation by the storage battery, the charge amount of the storage battery is not less than full charge and not more than full charge. It is an object of the present invention to provide a self-sustaining operation system and method for a distributed power source that can control charging of a storage battery by a solar battery without frequently switching.

A self-sustained operation system for a distributed power source according to the present invention is a self-sustained operation system for a distributed power source that reduces power supply from a commercial system, and is connected to the commercial system and supplied with power from the commercial system. A power converter that uses a storage battery to compensate for power fluctuations in the power supply system, a natural energy generator that generates power using natural energy, and supplies the power generated by the power generation to the power supply system, and the commercial system There is disconnected and the power supply system, when driving the load by said generated power to the battery of the natural energy generator power, in the charge control of the battery, the voltage of the storage battery naturally the exceeds the first threshold value stop operation of the energy generator, further comprising a resume controller operation between the condition of a preset charging start the natural energy power generator And butterflies.

  In the self-sustained operation system of the self-sustained distributed power source according to the present invention, when the control unit has a condition for starting operation of the natural energy generator, the voltage of the storage battery is equal to or lower than a second threshold value lower than the first threshold value, the natural energy The operation of the generator is started.

  In the self-sustained operation system of the self-sustained distributed power supply according to the present invention, the first threshold value is a voltage value indicating full charge, and the second threshold value is a specified voltage capable of driving the load. .

  In the self-sustained operation system of the self-sustained distributed power source according to the present invention, the control unit sets a stop time set in advance from the time when the voltage of the storage battery exceeds the first threshold and stops charging as the charge start condition. If it exceeds, the operation of the natural energy generator is started.

  The self-sustained operation system of the self-sustained distributed power supply according to the present invention is characterized in that the control unit sets the stop time in correspondence with the power consumption amount per unit time of the load.

The self-sustained operation method of the distributed power source of the present invention is a self-sustained operation method of the distributed power source that reduces the power supply from the commercial system, and the power is supplied from the commercial system in connection with the commercial system. A power conversion process that uses a storage battery to compensate for power fluctuations in the power supply system, and a natural energy power generation process that generates power using a natural energy generator that uses natural energy and supplies the generated power to the power supply system. And when the commercial system is disconnected from the power supply system and the load is driven by the generated power of the natural energy generator and the power of the storage battery, the voltage of the storage battery is a first threshold value in the charge control of the storage battery. the stop operation of the natural energy power generator exceeds resumes operation of the natural energy power generator and a condition of a preset charge start Characterized in that it comprises a control process.

  According to the present invention, during the self-sustained operation by the storage battery, when the generated power of the natural energy is large with respect to the important load, the amount of charge of the storage battery is not frequently switched between the full charge and the full charge, and the natural energy is used. Charging of the storage battery can be controlled, and deterioration of the mechanism due to continuous switching between power generation stop and power generation in a short cycle can be suppressed.

1 is a schematic block diagram illustrating a configuration example of a self-sustained operation system 10 for a distributed power source according to a first embodiment of the present invention. It is a wave form diagram explaining charge control of the independent operation system 10 in 1st Embodiment. It is a wave form diagram explaining charge control of the independent operation system 10 by 2nd Embodiment. It is a figure which shows the structural example of 10 A of independent operation systems of the distributed power supply by 3rd Embodiment of this invention. It is a figure which shows the prior art example of the system configuration for performing uninterrupted power supply at the time of the power failure at the time of commercial interconnection operation

<First Embodiment>
Hereinafter, a first embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a diagram showing a configuration example of a self-sustaining operation system (hereinafter, self-sustaining operation system 10) of a distributed power source according to a first embodiment of the present invention. In FIG. 1, 100 is an uninterruptible power supply, 101 is an input unit, 102 is an output unit, 103 is a voltage detection unit, 110 is a control unit, 120 is an AC semiconductor switch (ACSW), 130 is a storage battery, 135 is an INV (inverter) , Power conversion unit), 140 indicates a solar cell. Also, 145 is a PCS (power conditioner), 150 is an important load, 160 is a safety load, 170 is a disaster prevention load, 180 is a general load, 181 is a power detector, 190 is an emergency generator, and 191 is a first circuit breaker. , 192 indicates a second circuit breaker. Reference numeral 200 denotes a commercial power source, 201 denotes a power receiving point breaker, P1 denotes a power receiving point, and 400 denotes a power feeding line. In FIG. 1, a self-sustained operation system 10 supplies uninterrupted power supply to an important load 150 by an uninterruptible power supply device 100 at the time of a power failure during commercial interconnection operation (operation that performs system linkage with a commercial system). Do.

  In FIG. 1, the first self-supporting range (A) including the important load 150, immediately after the power failure and after the emergency generator 190 becomes unable to generate power due to fuel depletion, during operation of the emergency generator 190 during the power failure A second self-supporting range (B), which is a range that is self-supporting, is defined. The first self-sustained range (A) includes the input unit 101 in the self-sustained operation system 10 as viewed from the commercial power supply 200 side, and includes components connected to the rear stage side of the input unit 101. The second self-supporting range (B) includes the first circuit breaker 191 and includes each component connected to the rear stage side of the first circuit breaker 191.

The self-sustained operation system 10 includes an uninterruptible power supply 100, a PCS 145, a solar battery 140, an important load 150, a safety load 160, a disaster prevention load 170, a general load 180, a power detection unit 181, an emergency generator 190, a first circuit breaker 191. , And a second circuit breaker 192.
The general load 180 is connected to a power supply line by a commercial power source 200 that is a commercial system via a power receiving point P1, and when the power supply line falls into a power outage or other abnormal state, power reception is interrupted by the power receiving point circuit breaker 201.
The safety load 160 and the disaster prevention load 170 are loads for safety use, loads for disaster prevention use, and the like, are highly important loads, and are connected to the power supply line 400. The power supply line 400 is connected to the power receiving point P1 through the first circuit breaker 191 in the same manner as the general load 180.

  An emergency generator 190 is connected to the power supply line 400 via the second circuit breaker 192 and an important load 150 is connected via the AC switch 120. The important load 150 is supplied with electric power from the emergency generator 190 when the power supply line 400 fails. The important load 150 is a server, for example, and is a load having a higher importance than the security load 160 and the disaster prevention load 170. A storage battery 130 is connected to the connection line of the important load 150 via an inverter 135 in order to enable a self-sustained operation even when the power supply line 400 is interrupted and the emergency generator 190 is stopped. The solar cell 140 is connected via the conditioner 145.

  The emergency generator 190 uses heavy oil or other fuel as a power source, and is activated when the power supply line of the commercial power supply 200 falls into an abnormal state (that is, during a power failure). The emergency generator 190 is continuously operated during the occurrence of an abnormality, and supplies power to the safety load 160, the disaster prevention load 170, and the important load 150 in place of the commercial power source 200 within the second self-supporting range (B). Further, when the power supply line of the commercial power supply 200 continues to be in an abnormal state for a long time and the emergency generator 190 continues to operate for a long time, the fuel is exhausted (run out of fuel) and the operation is stopped. Even after the emergency generator 190 runs out of fuel, as long as the power generation by the solar cell 140 is maintained and the storage battery 130 is accumulating, the critical load 150 is within the first self-supporting range (A). Power supply continues.

  The storage battery 130 is, for example, a capacitor or a secondary battery that can be repeatedly charged and discharged, and is connected to the connection line of the important load 150 via the inverter 135. The storage battery 130 is appropriately charged by the commercial power source 200, the solar battery 140, and the emergency generator 190, and operates autonomously with respect to the safety load 160, the disaster prevention load 170, and the important load 150 (within the second independent range (B)). Or the critical load 150 (when the vehicle is operating independently within the first independent range (A)).

  The inverter 135 is a bidirectional power conversion device that performs bidirectional power conversion between alternating current and direct current. The inverter 135 uses the power of the storage battery 130 to compensate for power fluctuations in the power supply line 400. The inverter 135 converts AC to DC in the operation mode when charging the storage battery 130 from the commercial power source 200, the solar battery 140, and the emergency generator 190, and in the operation mode when discharging from the storage battery 130 to the important load 150. Converts direct current to alternating current. The inverter 135 has a built-in charge / discharge control circuit for controlling charge / discharge of the secondary battery. The charge / discharge control circuit receives a storage battery command value (control command value) from the control unit 110 described later, and controls charging / discharging of the secondary battery constituting the storage battery 130 according to the storage battery command value.

  The solar cell 140 is connected to the connection line of the important load 150 via the power conditioner 145 and supplies power generation output independently to the general load 180, the safety load 160, the disaster prevention load 170, and the important load 150. . The power conditioner 145 converts the DC output of the solar cell 140 that does not conform to the predetermined frequency and voltage of the connection line of the important load 150 into predetermined AC power, and adapts the frequency and voltage to the power of the power supply line. Moreover, in this embodiment, although the solar cell 140 is used, what is necessary is just the generator (natural energy generator) using natural energy, for example, you may use the generator by wind power generation, hydroelectric power generation, etc.

The first circuit breaker 191 is turned on during a normal load operation in which the power supply line of the commercial power supply 200 to which the general load 180 is connected is in a power supply state, and is opened (cut off) when the power supply line of the commercial power supply 200 is in a power failure state. .
The second circuit breaker 192 is opened when the first circuit breaker 191 is turned on and the power supply line of the commercial power supply 200 is in a power supply state, and the power supply line of the commercial power supply 200 enters a power failure state and the voltage of the emergency generator 190 Is established (a predetermined voltage on the connection line is reached). When the second circuit breaker 192 is turned on, the power generation output of the emergency generator 190 is fed to the safety load 160, the disaster prevention load 170, and the important load 150. Further, when the emergency generator 190 stops, the second circuit breaker 192 is opened.

The voltage detection unit 181 detects whether or not the power supply line of the commercial power supply 200 is out of power, and turns on / opens the first circuit breaker 191 and the second circuit breaker 192, and starts / stops the emergency generator 190. Take control. When the power supply line of the commercial power supply 200 fails, the voltage detection unit 181 detects the non-conduction of the power receiving point breaker 201, opens the first breaker 191 and activates the emergency generator 190 to After the voltage of the generator 190 is established, the second circuit breaker 192 is turned on. When the power failure of the power supply line of the commercial power source 200 is restored, the voltage detection unit 181 detects the continuity of the power receiving circuit breaker 201, turns on the first circuit breaker 191 and opens the second circuit breaker 192. Generator generator 190 is stopped.
The power detection unit 182 detects total power consumption by the total load including the important load 150 (excluding the power supply from the storage battery 130, the solar battery 140, and the emergency generator 190) at the power receiving point P1. Functions as power detection means. The power detection unit 182 transmits the detected detection value (received power point power) to the control unit 110.

The control unit 110, the AC switch 120, the inverter 135, the storage battery 130, the solar battery 140, the PCS 145, and the important load 150 are included in the first self-supporting range (A). When the commercial power source 200 is in a healthy state (including a return state) and power supply is required in the first self-supporting range (A), a tidal current flows in the AC semiconductor switch 120 in the forward direction. Thereby, the accumulator 130 and the important load 150 are supplied with AC power from the commercial power source 200 via the AC switch 120.
On the other hand, when the commercial power source 200 is in a power failure state, the AC switch 120 is cut off, and the supply of AC power from the commercial power source 200 is stopped. Further, when an abnormality occurs in the commercial power source 200, the AC semiconductor switch 120 is cut off as in the power failure state, and the supply of AC power from the commercial power source 200 is stopped. In this case, power from the storage battery 130 is supplied to the important load 150 via the output unit 102. Thereafter, when the emergency generator 190 starts generating power, the electric power from the emergency generator 190 is temporarily supplied to the important load 150 via the second circuit breaker 192 and the AC switch 120. Moreover, the power from the emergency generator 190 is supplied to the safety load 160 and the disaster prevention load 170 in the second self-supporting range (B). Thereafter, when the emergency generator 190 stops generating power, the AC switch 120 is cut off, and the electric power from the storage battery 130 is supplied again to the important load 150 via the output unit 102.

  Moreover, in the 1st self-supporting range (A), when the storage battery 130 is discharged or the solar battery 140 outputs and surplus power is generated, a power flow flows in the reverse direction in the AC switch 120. Thereby, even if the supply of AC power from the commercial power source 200 is stopped, power is supplied from the storage battery 130 and the solar battery 140 to the safety load 160 and the disaster prevention load 170 in the second self-supporting range (B). be able to.

The uninterruptible power supply 100 includes an AC switch 120, a storage battery 130, an inverter 135, a control unit 110, and a power detection unit 103 provided between the input unit 101 and the output unit 102. Inverter 135 is provided between AC switch 120 and storage battery 130. Although this control part 110 can also be comprised so that control by a higher-order controller etc. may be received, in this embodiment, the control part 110 shall control the uninterruptible power supply 100. FIG.
A power detection unit 103 is provided between the inverter 135 and the storage battery 130.
The power detection unit 103 detects a charging voltage that is a storage battery DC voltage in the storage battery 130, and transmits the detected detection value (referred to as a storage battery voltage) to the control unit 110.

The control unit 110 is a main controller for performing each control of the autonomous operation system 10 according to the present invention. The control unit 110 is configured by a general-purpose information processing device including, for example, a CPU (Central Processing Unit), a RAM (Random Access Memory), a ROM (Read Only Memory), and the like. The control unit 110 outputs a command (control command value, etc.) to a predetermined block based on the input predetermined information (detection value) by executing a program stored in the ROM in advance by the CPU on the RAM. I do.
The control unit 110 outputs a control signal and a control command value to the charge / discharge control circuit of the AC switch 120, the power conditioner 145, and the inverter 135, and controls them.

  The control unit 110 includes an internal storage unit 110a. In this internal storage unit 110a, two threshold voltages for charge control, a stop threshold voltage V1 and a start threshold voltage V2 lower than the stop threshold voltage V1, are written and stored in advance. The stop threshold voltage V1 is set as a voltage (for example, a voltage value of about 99% of full charge) that is slightly lower than the voltage at which the inverter 135 stops operating as a direct current overcharge voltage when the storage battery 130 is fully charged. On the other hand, the start threshold voltage V2 is slightly lower than the stop threshold voltage V1 (for example, a voltage value of about 90% of full charge) and within a voltage value range that exceeds the specification voltage at which the important load 150 can operate. Is set.

The power supply line of the commercial power supply 200 is cut off, the fuel of the emergency generator 190 is depleted, and the self-sustained operation in the first self-supporting range (A) is performed by the discharge of the storage battery 130 and the power generation of the solar battery 140. The control unit 110 performs charge control of the storage battery 130 as follows.
When the storage battery voltage supplied from the power detection unit 103 exceeds the stop threshold voltage V1, the control unit 110 determines that the storage battery voltage of the storage battery 130 exceeds the full charge and stops the operation of the power conditioner 145 (that is, natural The operation of the energy generator is stopped), and the supply of electric power from the solar cell 140 to the power supply line is stopped. Thereby, the power supply from the solar cell 140 to the power supply line is not performed, and the charging process for the storage battery 130 is stopped. Then, when the power is supplied to the important load 150 only by the power stored in the storage battery 130, the storage battery 130 is discharged.

  On the other hand, when the storage battery voltage supplied from the power detection unit 103 is equal to or lower than the activation threshold voltage V2, the control unit 110 starts the operation of the power conditioner 145, assuming that the storage battery 130 can be charged for a certain period of time. Supply of electric power from the solar cell 140 to the power supply line is started. Thereby, the electric power is supplied from the solar cell 140 to the power supply line, and when the generated power of the solar cell 140 is larger than the electric power supplied to the important load 150, the charging process for the storage battery 130 by the surplus electric power is performed. Done. Then, electric power is supplied to the important load 150 by the electric power stored in the storage battery 130 and the electric power generated by the solar battery 140, and as described above, the solar battery uses the electric power supplied to the important load 150. When the generated power 140 is large, the storage battery 130 is charged with the surplus power.

Next, FIG. 2 is a waveform diagram for explaining the charging control of the autonomous operation system 10 in the first embodiment. In FIG. 2, the vertical axis represents the storage battery DC voltage (charging voltage, unit V), and the horizontal axis represents time (t).
The charging control in the self-sustaining operation system 10 shown in FIG. 1 will be described with reference to FIG. Here, the power supply line of the commercial power supply 200 is cut off, the fuel of the emergency generator 190 is depleted, and the self-sustained area in the first self-sustaining range (A) is generated by the discharge of the storage battery 130 and the generated power of the solar battery 140. It is in a state where driving is performed. Further, the following description will be given assuming that the generated power of the solar cell 140 is larger than the power supplied to the important load 150.

Time t1:
The control unit 110 activates the power conditioner 145 when the storage battery voltage supplied from the power detection unit 103 is less than the activation threshold voltage V2 of the internal storage unit 110a and the power conditioner 145 is stopped.
Thereby, the power conditioner 145 supplies the generated power of the solar cell 140 to the power supply line.
As a result, electric power is supplied to the important load 150 from the storage battery 130 and the solar battery 140 via the power supply line (PCS (power conditioner 145) operation from time t1 to time t3).

Time t2:
The control unit 110 does not perform any processing although the storage battery voltage supplied from the power detection unit 103 reaches or exceeds the activation threshold voltage V2 of the internal storage unit 110a.

Time t3:
The control part 110 stops the power conditioner 145, when the storage battery voltage supplied from the electric power detection part 103 becomes more than the stop threshold voltage V1 of the internal storage part 110a.
Thereby, the power conditioner 145 stops the operation | movement which supplies the electric power generated by the solar cell 140 with respect to a feed line.
As a result, the important load 150 is supplied with electric power from the storage battery 130 via the power supply line, and the storage battery 130 is in a discharged state in which charging is not performed (from time t3 to time t5, the PCS (power conditioner 145). )Stop).

Time t4:
The control unit 110 does not perform any processing, although the storage battery voltage supplied from the power detection unit 103 becomes the stop threshold voltage V1 of the internal storage unit 110a from the voltage higher than the stop threshold voltage V1.

Time t5:
The control unit 110 activates the power conditioner 145 when the storage battery voltage supplied from the power detection unit 103 becomes less than the activation threshold voltage V2 of the internal storage unit 110a, similarly to the time t1.
Thereby, the power conditioner 145 supplies the generated power of the solar cell 140 to the power supply line.
As a result, the important load 150 is supplied with electric power from the storage battery 130 and the solar battery 140 via the feed line.

Time t6:
The control unit 110 does not perform any processing although the storage battery voltage supplied from the power detection unit 103 reaches the activation threshold voltage V2 of the internal storage unit 110a.

As described above, in the present embodiment, in the charging process for the storage battery 130, the control of the charge stop and the charge start is controlled using two thresholds having different voltage values of the stop threshold voltage V1 and the start threshold voltage V2, respectively. ing.
Thus, according to the present embodiment, the storage battery voltage for stopping the power conditioner 145 is determined based on the stop threshold voltage V1, and the storage battery voltage for starting the power conditioner 145 is started lower than the stop threshold voltage V1. Since the determination is made based on the threshold voltage V2, chattering processing for starting and stopping the power conditioner 145 at short intervals is eliminated, so that deterioration of the power conditioner 145 and the like can be suppressed.

<Second Embodiment>
Hereinafter, a second embodiment of the present invention will be described with reference to the drawings. The self-sustained operation system (hereinafter, self-sustained operation system 10) of the distributed power source in the second embodiment has the same configuration as that of the first embodiment shown in FIG.
Hereinafter, differences of the second embodiment from the first embodiment will be described.
The self-sustained operation system 10 of the distributed power source according to the second embodiment is different from the first embodiment in that when the control unit 110 starts the power conditioner 145 from the stop, the elapsed time after the stop is used. It is. That is, in the first embodiment, the control unit 110 stops the power conditioner 145 when the stop threshold voltage V1 is exceeded, and starts the power conditioner 145 when the start threshold voltage V2 or less is reached.

However, in the second embodiment, the control unit 110 stops the power conditioner 145 when the stop threshold voltage V1 is exceeded, and starts the power conditioner 145 when a predetermined time Ts has elapsed since the stop. . For this reason, the stop threshold voltage V1 and the time Ts are previously written and stored in the internal storage unit 110a of the control unit 110. This time Ts is determined and set based on the amount of stored power and the power consumption of the important load 150 when the storage battery 130 is fully charged, that is, the amount of discharged power per unit time. When this time Ts elapses, the storage voltage of the storage battery 130 becomes equal to or lower than the start threshold voltage V2 in the first embodiment.
Further, the control unit 110 has a counter (counter) inside, and counts (counts) time with this counter. Then, the control unit 110 compares the counted value (count) with the time Ts, and stops the operation of the power conditioner 145 when the count value becomes equal to or greater than the time Ts.

Next, FIG. 3 is a waveform diagram for explaining charging control of the autonomous operation system 10 according to the second embodiment. In FIG. 3, the vertical axis represents the storage battery DC voltage (charging voltage, unit V), and the horizontal axis represents time (t).
The charge control in the self-sustained operation system 10 according to the second embodiment will be described with reference to FIG. Here, the power supply line of the commercial power supply 200 is cut off, the fuel of the emergency generator 190 is depleted, and the self-sustained area in the first self-sustaining range (A) is generated by the discharge of the storage battery 130 and the generated power of the solar battery 140. It is in a state where driving is performed. Further, the following description will be given on the assumption that the generated power of the solar cell 140 is larger than the power supplied to the important load 150. In FIG. 3, the description will be made from the time when the power conditioner 145 is in an operating state.

Time t11:
The control part 110 stops the power conditioner 145, when the storage battery voltage supplied from the electric power detection part 103 becomes more than the stop threshold voltage V1 of the internal storage part 110a.
Further, after resetting the internal timer (set to “0”), the control unit 110 starts counting by this timer.
Thereby, the power conditioner 145 stops the operation | movement which supplies the electric power generated by the solar cell 140 with respect to a feed line.
As a result, power is supplied to the important load 150 from the storage battery 130 via the power supply line, and the storage battery 130 is in a discharged state in which charging is not performed (from time t11 to time t13, the PCS (power conditioner 145). )Stop).

Time t12:
The control unit 110 performs no processing when the storage battery voltage supplied from the power detection unit 103 is equal to or lower than the stop threshold voltage V1 of the internal storage unit 110a.

Time t13:
When the count value of the internal counter exceeds the time Ts of the internal storage unit 110a, the control unit 110 activates the power conditioner 145.
Thereby, the power conditioner 145 supplies the generated power of the solar cell 140 to the power supply line.
As a result, power is supplied to the important load 150 from the storage battery 130 and the solar battery 140 via the power supply line (PCS (power conditioner 145) operation after time t13).

As described above, in the present embodiment, in the charging process for the storage battery 130, the charging is stopped when the charging voltage becomes equal to or higher than the stop threshold voltage V <b> 1, and charging is started when the time Ts elapses after the charging is stopped. Control is in progress.
Thus, according to the present embodiment, the storage battery voltage for stopping the power conditioner 145 is determined based on the stop threshold voltage V1, and when the power conditioner 145 is started, the determination is made when a predetermined time Ts has elapsed since the stop. Therefore, it is possible to secure a certain period of time from when the power conditioner 145 stops until it starts. Thereby, since the chattering process which starts and stops the power conditioner 145 at a short interval is eliminated, it is possible to suppress the deterioration of the power conditioner 145 and the like.

<Third Embodiment>
The third embodiment of the present invention will be described below with reference to the drawings. FIG. 4 is a diagram showing a configuration example of a self-sustained operation system (hereinafter, self-sustained operation system 10A) of a distributed power source according to the third embodiment of the present invention. 4 is different from the first and second embodiments in FIG. 1 in that a switch 142 is interposed between the power supply line 400 and the power conditioner 145. It is that you are.
In the self-sustained operation system 10A of the first embodiment and the second embodiment, when charging the storage battery 130 is stopped, the power conditioner 145 is stopped and the generated power from the solar cell 140 is supplied to the power supply line 400. To prevent the output.
In the third embodiment, charging control for the storage battery 130 is performed by turning on and off the switch 142 without performing charging control for the storage battery 130 by stopping and starting the power conditioner 145.

Similar to the first embodiment, a case where the stop and start of the charging of the storage battery 130 are controlled using the stop threshold voltage V1 and the start threshold voltage V2 will be described below.
The power supply line of the commercial power supply 200 is cut off, the fuel of the emergency generator 190 is depleted, and the autonomous operation in the first autonomous range (A) is performed by the discharge of the storage battery 130 and the generated power of the solar battery 140. At this time, the control unit 110A performs charge control of the storage battery 130 as follows.
When the storage battery voltage supplied from the power detection unit 103 exceeds the stop threshold voltage V1, the control unit 110A turns off the switch 142 and sets the power conditioner 145 to the power supply line, assuming that the storage battery voltage of the storage battery 130 exceeds the full charge. Disconnecting from 400 (that is, stopping the operation of the natural energy generator), the supply of power from the solar cell 140 to the power supply line 400 is stopped. As a result, the power generated by the solar cell 140 is not supplied to the power supply line 400, and the charging process for the storage battery 130 is stopped. Then, when the power is supplied to the important load 150 only by the power stored in the storage battery 130, the storage battery 130 is discharged.

  On the other hand, when the storage battery voltage supplied from the power detection unit 103 becomes equal to or lower than the stop threshold voltage V2, the control unit 110A turns on the switch 142 and turns on the power conditioner 145, assuming that the storage battery 130 can be charged for a certain time. And the power supply line 400 are connected, and the supply of power from the solar cell 140 to the power supply line is started. Thereby, the electric power is supplied from the solar cell 140 to the power supply line, and when the generated power of the solar cell 140 is larger than the electric power supplied to the important load 150, the charging process for the storage battery 130 by the surplus electric power is performed. Done. Then, electric power is supplied to the important load 150 by the electric power stored in the storage battery 130 and the electric power generated by the solar battery 140, and as described above, the solar battery uses the electric power supplied to the important load 150. When the generated power 140 is large, the storage battery 130 is charged with the surplus power.

Next, similarly to the second embodiment, a case where the stop and start control of the storage battery 130 is performed using the stop threshold voltage V1 and the time Ts will be described below.
When the stop threshold voltage V1 is exceeded, the control unit 110A turns off the switch 142 and disconnects the power conditioner 145 and the power supply line 400 in order to stop charging the storage battery 130.
In addition, when a predetermined time Ts elapses after the switch 142 is turned off and charging is stopped, the control unit 110A turns on the switch 142 to start charging the storage battery 130, and the power conditioner 145 and the power supply line 400 is connected. That is, the control unit 110A has a counter (counter) inside, and counts (counts) time with this counter. Then, the control unit 110A compares the counted value (count) with the time Ts, and stops the operation of the power conditioner 145 when the count value exceeds the time Ts.

  Further, a program for realizing the functions of the control unit 110 in FIG. 1 and the control unit 110A in FIG. 4 is recorded on a computer-readable recording medium, and the program recorded on the recording medium is read by a computer system. You may perform the process of charge control with respect to the storage battery 130 by performing. Here, the “computer system” includes an OS and hardware such as peripheral devices.

Further, the “computer system” includes a homepage providing environment (or display environment) if a WWW system is used.
The “computer-readable recording medium” refers to a storage device such as a flexible medium, a magneto-optical disk, a portable medium such as a ROM and a CD-ROM, and a hard disk incorporated in a computer system. Furthermore, the “computer-readable recording medium” dynamically holds a program for a short time like a communication line when transmitting a program via a network such as the Internet or a communication line such as a telephone line. In this case, a volatile memory in a computer system serving as a server or a client in that case, and a program that holds a program for a certain period of time are also included. The program may be a program for realizing a part of the functions described above, and may be a program capable of realizing the functions described above in combination with a program already recorded in a computer system.

  The embodiment of the present invention has been described in detail with reference to the drawings. However, the specific configuration is not limited to this embodiment, and includes design and the like within a scope not departing from the gist of the present invention.

DESCRIPTION OF SYMBOLS 10,10A ... Self-sustained operation system 100 ... Uninterruptible power supply device 101 ... Input part 102 ... Output part 103 ... Voltage detection part 110, 110A ... Control part 110a ... Internal storage part 120 ... AC switch (ACSW)
130 ... Storage battery 140 ... Solar cell 142 ... Switch 145 ... Power conditioner (PCS)
DESCRIPTION OF SYMBOLS 150 ... Important load 160 ... Safety load 170 ... Disaster prevention load 180 ... General load 181 ... Voltage detection part 182 ... Electric power detection part 190 ... Emergency generator 191 ... First circuit breaker 192 ... Second circuit breaker 200 ... Commercial power supply 201 ... Power receiving point breaker 400 ... Power supply line P1 ... Power receiving point

Claims (6)

This is a self-sustaining operation system for distributed power sources that reduces power supply from commercial systems.
A power conversion unit that performs power grid compensation with a power storage system connected to the commercial system using a storage battery.
A natural energy generator that generates power using natural energy and supplies power generated by the power generation to the power supply system;
When the commercial system is disconnected from the power supply system and the load is driven by the generated power of the natural energy generator and the power of the storage battery, the voltage of the storage battery exceeds a first threshold in the charge control of the storage battery. autonomous operation system of a distributed power source, characterized in that it comprises the said stop operation of natural energy generator resumes control unit the operation of the condition of a preset charging start the natural energy power generator with. The control unit is
As a condition for starting the charging, the operation of the natural energy generator is started when the voltage of the storage battery is equal to or lower than a second threshold lower than the first threshold.
The self-sustained operation system for a distributed power source according to claim 1.   3. The distributed power supply self-sustained operation system according to claim 2, wherein the first threshold value is a voltage value indicating full charge, and the second threshold value is a specified voltage enabling the load to be driven. . The control unit is
As a condition for starting the charge, when the voltage of the storage battery exceeds the first threshold and the operation of the natural energy generator is stopped, when the preset stop time is exceeded, the operation of the natural energy generator is started.
The self-sustained operation system for a distributed power source according to claim 1. The control unit is
The self-sustained operation system for a distributed power source according to claim 4, wherein the stop time is set in correspondence with an amount of power consumption in a unit time of the load. This is a self-sustaining operation method for distributed power sources that reduces power supply from commercial systems.
Power conversion process using a storage battery to compensate for power fluctuations in a power supply system that is connected to the commercial system and supplied with power from the commercial system;
A natural energy power generation process in which power is generated by a natural energy generator using natural energy, and power generated by the power generation is supplied to the power supply system;
When the commercial system is disconnected from the power supply system and the load is driven by the generated power of the natural energy generator and the power of the storage battery, the voltage of the storage battery exceeds a first threshold in the charge control of the storage battery. the stop operation of the natural energy power generator, autonomous operation method of distributed power supply, which comprises a predetermined resume control step the operation of the natural energy power generator and a condition of the charging start with.

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