JP6961195B1 - Power control systems, power control methods, and power control programs - Google Patents

Abstract

We provide a power control system, power control method, and power control program that can automatically determine the operating area of reverse power flow prevention control by a power generation device that generates power using demand control and renewable energy, and realize a stable supply of power. do. PROBLEM TO BE SOLVED: To provide a demand control for suppressing power consumption with respect to an on-site load 40 based on a power flow power supplied from a commercial power system, and a reverse power flow by a power generation system 30 for generating power based on renewable energy. Perform preventive control. The control unit 20 determines a demand control area and a reverse power flow prevention control area based on the power flow power detected by the switching determination unit 201, and switches between demand control and reverse power flow prevention control according to the determination result. It is possible to perform different controls with one control system. [Selection diagram] Fig. 1

Description

The present invention relates to power control systems, power control methods, and power control programs. Specifically, a power control system, a power control method, and a power control that can automatically determine the operating area of reverse power flow prevention control by a power generation device that generates power by demand control and renewable energy and realize a stable supply of power. It is related to the program.

Generally, the electricity charges of electric power companies (excluding household electricity charges) are calculated by the "basic charge" determined by the contracted electricity and the "electric energy charge" determined by the amount of electricity used. Of these, the contracted power has a mechanism in which the annual basic charge is determined by the average power for 30 minutes. Of the electric loads, the power consumption of the air conditioner is the largest, and the combined power consumption of the air conditioner and the lighting device accounts for about 72% of the total power consumption. Therefore, saving power in the air conditioner is extremely effective as a power saving measure.

Air conditioners are generally composed of outdoor units and indoor units. Of these, many outdoor units of air conditioners installed outdoors are operated by electric motors such as compressors with signals from each indoor unit. The outdoor unit repeatedly stops operating individually without cooperating with other outdoor units. Therefore, when all the outdoor units are operated at the same time, the power demand (demand) rises sharply.

Therefore, it is conceivable to introduce demand control as a method of suppressing the maximum demand power (contract power) and perform coordinated operation of a plurality of air conditioners for outdoor units. Here, the demand control is a control for avoiding an increase in demand by avoiding the simultaneous operation of a plurality of units in the outdoor unit of the air conditioner. In other words, it is an operation control that outputs an operation stop signal to the outdoor unit of some air conditioners when the maximum demand power is expected.

As a conventional technique relating to demand control, for example, in Patent Document 1, a demand control signal is output only to a load capable of automatically controlling power among all loads to which power is supplied from a power company via a power receiving point. A control device characterized by this is disclosed. According to the technique of Patent Document 1, since demand control is performed for a load capable of automatically controlling power, appropriate management of power consumption is performed while avoiding a decrease in production efficiency due to a load that is not subject to demand control. Can be done.

By the way, in recent years, a power generation device that generates electric power by using renewable energy such as solar power generation, or a power management system including a power storage device is known (see, for example, Patent Document 2). A power generation device using such renewable energy is generally connected to a power grid of a commercial power system. Then, for example, on holidays when the production equipment or the like does not operate, the amount of electric power generated by the power generation device becomes larger than the power consumption. Therefore, in order to prevent reverse power flow from the power generation device to the commercial power system, it is required to stop the power generation by the power generation device.

However, if it is possible to generate electricity from renewable energy as much as possible even on holidays, it is possible to reduce electricity charges and carbon diacid emissions. Further, by storing the surplus electric power generated by the power generation device in the power storage device, it can be used as an emergency power source. Therefore, in general, reverse power flow prevention control is performed to suppress the power generation of the power generation device to the extent that the reverse power flow of the generated power does not occur according to the power consumption.

Japanese Patent No. 5606645 Japanese Unexamined Patent Publication No. 2005-185016

The power control system that performs demand control or reverse power flow prevention control disclosed in the above-mentioned conventional technology is a system that detects the amount of power supplied from the power company by a power flow detector and then performs feedback control. However, they were installed as separate power control systems. Therefore, it is necessary to install a control device according to each purpose for the demand control for the load and the reverse power flow prevention control of the power generation device by the renewable energy, and the introduction cost is very high.

The present invention has been devised in view of the above points, and realizes a stable supply of electric power by automatically determining the operating region of reverse power flow prevention control by a power generation device that generates electric power by demand control and renewable energy. It relates to a power control system, a power control method, and a power control program that can be used.

In order to achieve the above object, the power control system of the present invention has a power flow detection unit that detects power flow power supplied from a commercial power system, and a demand signal in which the power consumption of the load is a predetermined demand target value. A power generation system having a demand signal output unit that outputs to the load, a power generation device that generates power from renewable energy, and a power converter that outputs the generated power generated by the power generation device, and the power generation device. In a power control system including a power generation signal output unit that controls the amount of power generation and outputs a power generation signal for preventing the reverse power flow of the generated power to the commercial power system to the power generation system, the power flow power is used as the power generation signal. Based on this, it has a control unit including a demand signal output unit and an output switching unit for switching an output signal to be output to the power generation signal output unit, and the control unit has a control unit when the power flow power is equal to or higher than a predetermined threshold value. Outputs the demand signal from the output switching unit to the demand signal output unit, and when the power flow power is less than a predetermined threshold value, the output switching unit outputs the power generation signal to the power generation signal output unit. Is output.

Here, by providing the power flow detection unit that detects the power flow power supplied from the commercial power system, the power flow power supplied to the load from the commercial power system can be detected, so that the detected power flow power Based on the above, the demand control described later or the reverse power flow prevention control can be executed.

Further, by providing a demand signal output unit that outputs a demand signal whose load power consumption is a predetermined demand target value to the load, the demand signal is output to the load so as to be the set demand target value. This makes it possible to execute demand control that suppresses the load to a predetermined power consumption.

In addition, by equipping a power generation device that generates power from renewable energy (for example, solar power or wind power), the generated power is generated based on the renewable energy, and the tidal current power supplied from the commercial power system is a system. Power can be supplied to the load by linking.

Further, by providing a power converter that outputs the generated power generated by the power generation device, it is possible to convert the DC power generated based on the renewable energy into AC power so that it can be linked to the power system.

Further, by providing a power generation signal output unit that controls the amount of power generated by the power generation device and outputs a power generation signal that prevents reverse power flow of the generated power to the commercial power system to the power generation system, for example, power is generated by the power generation device. When the power generated based on renewable energy suddenly increases or the power consumption of consumers suddenly decreases, reverse power flow prevention control is executed to prevent part of the power flow from flowing into the commercial power system, and the commercial power system Stable operation can be realized.

Further, by having a control unit including a demand signal output unit and an output switching unit for switching the output signal to be output to the power generation signal output unit based on the power flow power, one control unit can control the demand for the load and the power generation system. The reverse power flow prevention control can be appropriately switched.

Generally, on weekdays when factories and the like operate, the load power is large and the demand for demand control is high. On the other hand, on weekends when the factory is closed, the load power becomes smaller, so the demand for reverse power flow prevention control increases. Therefore, based on the power flow power supplied to the load from the commercial power system, it is determined whether it is a demand control area or a reverse power flow prevention control area based on a predetermined threshold value, and based on the determination result, demand control and reverse power flow prevention control are performed. It is possible to switch between and instantly.

Further, when negative control is performed to control the output of the load so that the difference between the power consumption and the demand target value becomes zero by the demand signal output from the demand signal output unit, the power consumption of the load is instantaneous. Even if it rises to, the power consumption of the load is suppressed so as not to exceed the demand target value based on the demand control. Therefore, since the power consumption of the load is always suppressed within the demand target value, it is possible to prevent the load power consumption from exceeding the maximum demand power.

In addition, when positive control is performed to increase the output value of the generated power in proportion to the input value of the power consumption by the power generation signal output from the power generation signal output unit, the increase in the power consumption is based on the renewable energy. It can be supplemented by generated power. Therefore, the tidal current power supplied from the commercial power system can be suppressed.

Further, the demand signal output unit executes the first proportional control that outputs the first demand signal to the load so that the power consumption becomes less than the demand target value, and sets in advance from the start of the first proportional control. Control when executing the second proportional control that outputs a second demand signal corresponding to the change in power consumption to the load after the delay time considering the response delay time of the applied load has elapsed. It is possible to prevent hunting and execute stable demand control.

That is, in general, the load that receives the demand signal from the demand signal output unit is suppressed in power consumption so as to reach the demand target value, but it is predetermined from the time when the demand signal is received until the power consumption is suppressed. Response delay time occurs. If demand control is executed without considering this response delay time, the power consumption of the load is significantly suppressed with respect to the target value. At this time, in order to correct the deviation from the target value, control hunting occurs by outputting a signal that increases the power consumption with respect to the load. Therefore, by considering the response delay time due to the load, the control hunting described above can be prevented and stable demand control can be executed.

Further, the demand setting unit for setting the demand target value has a variable resistance whose resistance value changes with the rotation of the dial, and the demand target value is set based on the resistance value of the variable resistance set by the rotation of the dial. In that case, the demand target value can be easily set by simply rotating the dial.

In addition, it has a display unit that displays the demand target value set by the demand setting unit and the deviation of power consumption, and the display unit consists of a voltage dividing resistor and a plurality of constant voltage diodes that light up at different operating voltages. When the voltage circuit is included, as a result of the demand control, the deviation between the demand target value and the power consumption can be visually confirmed. Therefore, it is possible to monitor the state of the power consumption of the load after the execution of the demand control without allocating a specialized worker.

In addition, it has a demand guarantee unit that sets a demand guarantee target value that is approximately 50 to 80% of the demand target value. On the other hand, when the fail-safe demand signal based on the demand guarantee target value is output, the demand control for the load can be continued even if the power flow detection unit fails, so that the increase in the maximum demand power should be prevented. Can be done.

That is, the tidal current power detection unit may fail due to a lightning strike or the like. At this time, if the demand signal output unit erroneously determines that the power demand of the load has decreased and outputs the demand signal in the direction of increasing the demand target value, the inconvenience that the maximum demand power increases occurs. In order to prevent this, if it is determined that the tidal current power is not detected, it is determined that the tidal current power detector has failed, and the load power consumption is suppressed to a predetermined value with respect to the demand target value. By outputting the above-mentioned problem, the above-mentioned trouble can be prevented.

Further, it has a power generation guarantee unit that sets an abnormal power flow power that is a lower limit threshold of the power flow power that is set based on the power consumption of the load, and the power generation guarantee unit determines that the power generation power is less than the abnormal power flow power. And, when outputting a fail-safe power generation signal that controls the power generation system to approximately 2 to 5% of the maximum power generation power of the power generation system, reverse power flow from the power generation system to the commercial power system is reliably prevented. At the same time, it is possible to prevent damage to the power converter and perform stable power generation control.

That is, when the power consumption of the load becomes less than the preset abnormal power flow power for some reason, it is generally required to stop the power generation by the power generation system in order to prevent the reverse power flow. However, each time the power generation system is stopped, it is necessary to execute on / off control of the electromagnetic switch built in the power converter. Repeated on / off control of the electromagnetic switch causes damage to the electromagnetic switch and increases maintenance costs.

Therefore, when the power flow becomes less than the abnormal power flow, a fail-safe power generation signal is output to the power generation system so as to output power generated to the extent that reverse power flow from the power generation system to the commercial power system does not occur. As a result, the electromagnetic switch can be kept on at all times, and damage to the electromagnetic switch can be prevented while preventing reverse power flow.

In order to achieve the above object, the power control method of the present invention uses a power flow detection unit that detects power flow power supplied from a commercial power system and a demand signal in which the power consumption of the load becomes a predetermined demand target value. A power generation system having a demand signal output unit that outputs to the load, a power generation device that generates power from renewable energy, and a power converter that outputs the generated power generated by the power generation device, and the power generation device. A power generation signal output unit that controls the amount of power generation and outputs a power generation signal that prevents the reverse power flow of the generated power to the commercial power system to the power generation system, and the demand signal output based on the power flow power. In the power control method of a power control system including a unit and a control unit having an output switching unit for switching an output signal output to the power generation signal output unit, a step of determining whether or not the power flow power is equal to or higher than a predetermined threshold value. When it is determined that the power flow power is equal to or higher than a predetermined threshold value, the output switching unit outputs the demand signal to the demand signal output unit, and the power flow power is less than the predetermined threshold value. A step of outputting the power generation signal from the output switching unit to the power generation signal output unit when it is determined to be present is provided.

Further, in order to achieve the above object, the power control program of the present invention includes a power flow detection unit that detects power flow power supplied from a commercial power system, and a demand that the power consumption of the load becomes a predetermined demand target value. A power generation system having a demand signal output unit that outputs a signal to the load, a power generation device that generates power from renewable energy, and a power converter that outputs the power generated by the power generation device, and the power generation. A power generation signal output unit that controls the amount of power generated by the device and outputs a power generation signal for preventing the reverse power flow of the generated power to the commercial power system to the power generation system, and the demand based on the power flow power. A program executed by the control unit of a power control system including a signal output unit and a control unit having an output switching unit for switching an output signal output to the power generation signal output unit, wherein the power flow power is a predetermined threshold value. A step of determining whether or not the above is the case, and a step of outputting the demand signal from the output switching unit to the demand signal output unit when it is determined that the power flow power is equal to or greater than a predetermined threshold value. When it is determined that the tidal current power is less than a predetermined threshold value, the output switching unit includes a step of outputting the power generation signal to the power generation signal output unit.

In the above power control method and power control program, the power flow power supplied from the commercial power system to the load is detected by providing the power flow power detection unit for detecting the power flow power supplied from the commercial power system. Therefore, it is possible to execute the demand control or the reverse power flow prevention control described later based on the detected power flow.

Further, by providing a demand signal output unit that outputs a demand signal whose load power consumption is a predetermined demand target value to the load, the demand signal is output to the load so as to be the set demand target value. Therefore, the load can be suppressed to a predetermined power consumption.

In addition, by equipping a power generation device that generates power from renewable energy (for example, solar power or wind power), the generated power is generated based on the renewable energy, which is different from the tidal current power supplied from the commercial power system. Power can be supplied to the load in the grid.

Further, by providing a power converter that outputs the generated power generated by the power generation device, it is possible to convert the DC power generated based on the renewable energy into AC power so that it can be linked to the power system.

In addition, by providing a power generation signal output unit that controls the amount of power generated by the power generation device and outputs a power generation signal to the power generation system to prevent reverse power flow of the generated power to the commercial power system, a range in which reverse power flow does not occur. In, it is possible to control the amount of power generated based on renewable energy and realize stable operation of a commercial power system.

By providing a control unit having a demand signal output unit and an output switching unit for switching the output signal to be output to the power generation signal output unit based on the power flow power, one control unit can control the demand for the load and reverse the power generation system. The power flow prevention control can be switched as appropriate.

Then, a step (step) of determining whether or not the power flow power is equal to or higher than a predetermined threshold value, and when it is determined that the power flow power is equal to or higher than a predetermined threshold value, the output switching unit sends the demand signal output unit to the demand signal output unit. It includes a step of outputting a demand signal and a step of outputting a power generation signal from the output switching unit to the power generation signal output unit when it is determined that the power flow power is less than a predetermined threshold value. As a result, in one power control system, the operating areas of the demand control area and the reverse power flow prevention control area can be determined based on the power flow power, and the demand control and the reverse power flow prevention control can be switched instantly according to the determination result. It will be possible.

The electric power control system, the electric power control method, and the electric power control program according to the present invention automatically determine the operating area of reverse power flow prevention control by a power generation device that generates electric power by demand control and renewable energy, and realize a stable supply of electric power. It has become something that can be done.

It is an overall schematic diagram of the power control system which concerns on embodiment of this invention. It is a figure which shows the operating area of demand control and reverse power flow prevention control. It is a figure which shows the operation part for setting a demand target value. It is a figure which shows the circuit diagram of the demand setting part. It is a graph which shows the relationship between the load power and the power consumption in demand control. It is a figure which shows the circuit diagram of the lighting display part. It is a graph which shows the relationship between a demand signal and a load output signal. It is a graph which shows the relationship between the load power and the generated power in power generation control.

Hereinafter, embodiments of the present invention will be described with reference to the drawings for the purpose of understanding the present invention. First, an overall outline of the power control system according to the embodiment of the present invention will be described with reference to FIG.

The power control system 1 according to the embodiment of the present invention includes a power flow detection unit 10 that detects power flow power supplied from a power network, a control unit 20 that switches between demand control and reverse power flow prevention control, and power generation that generates power by renewable energy. It is mainly composed of the system 30.

[Tide detector]
The power flow detection unit 10 has a function of detecting the power flow power (instantaneous power) flowing from the power grid of the commercial power system provided by the electric power company. The tidal current power detected by the tidal current detecting unit 10 is output as a tidal current signal. Then, based on the tidal current signal output from the tidal current detecting unit 10, demand control for the on-site load 40 or reverse power flow prevention control for the power generation system 30 is executed as described later.

Further, the tidal current detection unit 10 detects the real-time tidal current power flowing through all the on-site loads 40, and does not detect the electric energy in a predetermined sampling period. A DC analog signal (DC 4 to 20 mA, or 1 to 5 V) is used as the tidal current signal output from the tidal current detection unit 10, but a wide variety of digital signals corresponding to this may be used.

Here, the tidal current power detected by the tidal current detecting unit 10 does not necessarily have to be detected in real time, and may be an average value of a predetermined sampling period. However, by detecting the power flow in real time, demand control and reverse power flow prevention control can be performed more accurately.

[Control unit]
The control unit 20 has a function of switching between demand control for the on-site load 40 and reverse power flow prevention control for the power generation system 30 based on the power flow power detected by the power flow detection unit 10. In the control in the control unit 20, when the output signal from the power flow detection unit 10 is first input to the control unit 20, the switching determination unit 201 determines whether to execute the demand control or the reverse power flow prevention control. ..

As shown in FIG. 2, when the switching determination unit 201 determines that the tidal current power input from the tidal current detection unit 10 is 200 kW or more, a signal instructing the control switching unit 202 to execute demand control is sent. It is output. Upon receiving the signal instructing the execution of the demand control, the control switching unit 202 executes the demand control for the on-site load 40 based on the demand target value set by the demand setting unit 203.

On the other hand, when the switching determination unit 201 determines that the power flow power input from the power flow detector is less than 200 kW, a signal instructing the control switching unit 202 to execute the reverse power flow prevention control is output. Upon receiving the signal instructing the execution of the reverse power flow prevention control, the control switching unit 202 executes the reverse power flow prevention control for the power generation system 30 based on the power generation amount set by the power generation amount setting unit 204.

Here, in the switching control of the demand control and the reverse power flow prevention control in the control switching unit 202, it is not always necessary to set the power flow power to 200 kW as a threshold value, and the control switching threshold value can be appropriately changed.

Further, it is not always necessary to use power flow power as a parameter for switching between demand control and reverse power flow prevention control in the control unit 20. For example, based on date data, demand control is executed on weekdays when the power consumption of the on-site load 40 increases. However, on holidays when the power consumption of the on-site load 40 decreases, the reverse power flow prevention control may be switched to be executed.

[Demand control]
When the control switching unit 202 receives the signal for executing the demand control, the demand control is executed. In the demand control, a control signal (demand signal) for controlling the power consumption of the on-site load 40 to the power consumption of the demand target value set by the demand setting unit 203 is output to the on-site load 40.

In the embodiment of the present invention, as shown in FIG. 1, A, A', B, and B'are assumed as the on-site load 40, and among these, the loads A and A'that can automatically control the electric power Therefore, it is assumed that the demand signal is output and the demand control is executed.

Here, the loads A and A'are, for example, a load capable of automatically controlling electric power and having little influence even if the output is controlled, for example, an air conditioner installed in a factory or an office building. be. On the other hand, the loads B and B'are loads for which automatic control of electric power is impossible, and when output control is performed, they are devices that have a great influence on production and the like, and are, for example, production equipment.

Further, in the embodiment of the present invention, an air conditioner is mentioned as a load capable of automatically controlling electric power, but it may be a facility such as a lighting device which does not have a great influence on production or social activities by demand control. There is no particular limitation. Furthermore, although production equipment is mentioned as a load for which automatic control of electric power is not possible, it is also possible to target, for example, medical machines, kitchen machines, and the like.

The demand setting unit 203 can be set to an arbitrary demand value by rotating the dial 101 of the operation unit 100 shown in FIG. 3, for example. The operation unit 100 includes a demand display unit 102 that displays the current demand value and a target demand display unit 103 that displays the target demand value 103 set by the dial 101 so that the operator can monitor each demand value. It has become.

FIG. 4 is a diagram showing an electric circuit in the demand setting unit 203. The demand setting unit 203 includes a variable resistor R, and the resistance value changes depending on the rotation angle thereof, so that the applied voltage input to the amplifier also changes.

The demand target value set by the demand setting unit 203 is output to the target value setting unit 205. Then, the deviation between the tidal current power detected by the tidal current detection unit 10 and the demand target value is calculated by the comparison unit 206. The calculation result by the comparison unit 206 is input to the adjustment unit 207 as a demand comparison signal.

When a demand comparison signal is input to the adjusting unit 207, it is corrected to a value according to a predetermined sensitivity, and the demand signal S _D1 for controlling the power consumption of the loads A and A'which are the demand control targets is output-switched. It is output from the unit 208 to the loads A and A'through the demand signal output unit 60.

FIG. 5 is a graph showing the relationship between the load power (input value) and the power consumption (output value) of the loads A and A ′ in the demand control. As shown in FIG. 5, when the load power is set to 500 kW as the demand target value, the difference between the power consumption and the demand target value becomes zero as the load power of the loads A and A'increases. The demand signal S _D1 is output, and as a result, the power consumption is reduced. That is, in the demand control, the negative feedback control is performed in which the input value and the output value are opposite to each other.

The result of demand control can be displayed to the operator in real time. For example, as in the electric circuit of FIG. 6, the voltage output from the amplifier is divided by a voltage dividing circuit provided with a plurality of resistors R1, R2, and R3, and connected to the constant voltage diodes D1, D2, and D3, respectively. Here, by using the constant voltage diodes D1, D2, and D3 having different emission colors according to the operating voltage, different display colors are displayed depending on the output voltage.

The display colors of the constant voltage diodes D1, D2, and D3 can be arbitrarily set. For example, if the power consumption with respect to the demand target value is 80%, it is blue, if it is 70%, it is green, if it is less than 50%, it is red, and so on, depending on the deviation between the demand target value and the power consumption. By switching the emission color and displaying it on the lighting display unit 104 of the operation unit 100, the operator can visually grasp the result of the demand control in real time.

Here, the display modes of the constant voltage diodes D1, D2, and D3 are not necessarily limited to those described above. The range of deviation between the demand target value and the power consumption and the display color corresponding to the range can be arbitrarily changed.

FIG. 7 is a graph showing the relationship between the power consumption of the loads A and A', which are the targets of demand control, and the demand signal S _{D1. First, when the power consumption of the loads A and A'increases, the demand signal S D1} is output in the direction in which the power consumption is suppressed with respect to the loads A and A'as shown by reference numerals a to b in FIG. .. At this time, the power consumption of the loads A and A'work in a direction of being suppressed, but in general, the response speed of the loads A and A'has a response delay of about 30 to 60 seconds or more. _{If the demand signal S D1} is output in the direction of further suppressing the power consumption from b to c without considering this response delay, the power consumption will be excessively reduced, and if this is left unattended, control hunting will occur, resulting in control hunting. Stable demand control cannot be realized.

To prevent the above hunting phenomenon, _{the output of the demand signal S D1 in} b is maintained for the time d (about 30 to 60 seconds) in consideration of the response delay time of the loads A and A', so that the load A is prevented. , It is possible to eliminate the influence of the response delay of the power consumption of A'. Then, since the adjusting unit 207 starts proportional control again from e, the adjusting unit 207 can execute stable demand control without causing a hunting phenomenon.

Here, the standby time (d) from the output of the demand signal S _D1 does not necessarily have to be about 30 to 60 seconds. The standby time (d) can be appropriately changed according to the type of the load 40 in the hall.

[Power generation system]
The power generation system 30 according to the embodiment of the present invention will be described. The power generation system 30 converts the solar panel 301 as a power generation device that generates electric power based on renewable energy (solar in the embodiment of the present invention) and the electric power generated by the solar panel 301 from DC to AC. A power converter 302 that converts and outputs to the on-site load 40 via the power branch 110, and a power generation detection unit 303 that detects the amount of power generated by the solar panel 301 and outputs a power generation signal. And have.

[Reverse power flow prevention control]
When the control switching unit 202 receives the signal for executing the reverse power flow prevention control, the reverse power flow prevention control for the power generation system 30 is executed. Generally, when the power consumption of the on-site load 40 is large as on weekdays, a power generation signal is output to the power generation system 30 according to the deviation between the tidal current power and the power generation target value by the power generation system 30. Then, the generated power generated by the power generation system 30 based on the power generation signal is constantly supplied to the on-site load 40, so that the tidal current power can be kept constant.

FIG. 8 is a graph showing the relationship between the load power (input value) of the on-site load 40 and the power generated (output value) by the power generation system 30. As shown in FIG. 8, as the load power of the on-site load 40 increases, the power generation signal is output so that the power generated by the power generation system 30 also increases. That is, in the power generation control, the positive feedback control is performed in which the input value and the output value have the same movement.

On the other hand, when the power consumption of the on-site load 40 is small as in a holiday, the power generated by the power generation system 30 becomes excessive with respect to the power consumption. If this state is left unattended, a reverse power flow will occur in which the generated power generated by the power generation system 30 flows back to the commercial power system, which causes instability of the commercial power system. The reverse power flow prevention control is a control for suppressing the power generated by the power generation system 30 in order to prevent this reverse power flow and keep the power flow power at a constant value.

As shown in FIG. 2, when the power flow power input from the power flow detection unit 10 is less than 200 kW, it is determined that there is a high possibility that reverse power flow will occur, and the switching determination unit 201 is connected to the control switching unit 202. On the other hand, a signal for executing reverse power flow prevention control is output.

When the control switching unit 202 receives the signal for executing the reverse power flow prevention control, the power generation amount set by the power generation amount setting unit 204 is output to the target value setting unit 205. Next, the power generation amount input to the target value setting unit 205 and the power generation amount of the power generation system 30 detected by the power generation amount detection unit 303 are compared by the comparison unit 206, and are input to the adjustment unit 207 as a power generation amount comparison signal. .. When power generation amount comparison signal is inputted in the regulation unit 207, after the power generation signal S _E1 corrected to a value corresponding to a predetermined sensitivity is signal conversion by the signal conversion unit 304 from the output switching section 208, the power generation signal output unit It is output to the power generation system 30 through 70.

In the reverse power flow prevention control, a part of the generated power generated by the power generation system 30 is supplied to the on-site load 40, and a part is instructed to be charged to a charging device (not shown) to generate the reverse power flow. It is also possible to prevent it.

[Demand Guarantee Department]
Next, the fail-safe function of demand control will be described. The fail-safe function of the demand control is executed by the demand guarantee unit 80. When the loads A and A'are in normal operation, as described above, the tidal current power detected by the tidal current detecting unit 10 and the demand target value set by the demand setting unit 203 are compared by the comparing unit 206, and the result is obtained. The demand signal S _D1 corresponding to the above is output from the output switching unit 208 to the loads A and A'through the demand signal output unit 60.

On the other hand, if the power flow detection unit 10 fails to detect the power flow power due to a failure of the power flow detection unit 10 due to the influence of a lightning strike or the like during execution of the demand control, the adjustment unit 207 has a margin for the demands of the loads A and A'. _{Is determined to have occurred, and the demand signal S D1} is output in the direction in which the power consumption of the loads A and A'increases. As a result, the power consumption of the loads A and A'is increased without executing normal demand control, and exceeds the maximum demand power. Then, the state in which the power consumption of the loads A and A'exceeds the maximum demand power continues for a predetermined time, so that the contract amount with the electric power company may fluctuate.

In order to prevent this, the demand guarantee unit 80 determines that the tidal current detection unit 10 has failed when the tidal current power E1 is not detected by the tidal current detection unit 10 (E1 = 0). The demand assurance unit 80 outputs a demand switching signal S _R1 to demand signal output unit 60.

Upon receiving the demand switching signal S _R1 in a demand signal output section 60, a fail-safe demand signal as a preset demand guaranteed target value in a demand guarantee section 80 (target value is suppressed to substantially about 70% of the demand target value) S _D2 is output, and the demand signal S _D2 is output from the demand signal output unit 60 to the loads A and A'. As a result, even if the tidal current detection unit 10 fails for some reason and the tidal current power is not detected, the demand control for the loads A and A'is continued.

[Power Generation Guarantee Department]
Next, the fail-safe function in reverse power flow prevention control will be described. The fail-safe function of reverse power flow prevention control is executed by the power generation guarantee unit 90. In the reverse power flow control when the load 40 in the field operates normally, as described above, the power flow power detected by the power flow detection unit 10 and the power generation amount set by the power generation amount setting unit 204 are compared by the comparison unit 206, and as a result. The power generation signal _SE1 corresponding to the above is output from the output switching unit 208 to the power generation system 30.

On the other hand, when the power consumption of the on-site load 40 suddenly decreases and the power flow power E1 detected by the power flow detection unit 10 temporarily becomes a low value, if the power generation signal _SE1 is continuously output to the power generation system 30, the power generation system There is a risk of reverse power flow from 30 to the commercial power system.

In order to prevent this, in the power generation guarantee unit 90, the power flow power E1 detected by the power flow detection unit 10 and the abnormal power flow power E2 preset by the power generation guarantee unit 90 are compared, and E1 <E2. In this case, the power generation switching signal S _R2 is output to the power generation signal output unit 70. When the power generation signal output unit 70 _{receives the power generation switching signal S R2 , the power generation guarantee unit 90 sends a fail-safe power generation signal S E2 which} is about 2 to 5% of the maximum power generation power of the power generation system 30 to the power generation signal output unit 70. It is output to the power generation system 30 through.

As a result, even if the power consumption of the on-site load 40 suddenly decreases for some reason and the power flow power generated by the power flow detection unit 10 temporarily becomes a low value, the reverse power flow from the power generation system 30 to the commercial power system is prevented. be able to. Further, even if the power consumption of the on-site load 40 suddenly decreases, the power generation can be continued without stopping the power generation by the power generation system 30, so that the power generation system can be operated stably.

As described above, in the embodiment of the present invention, the demand control and the reverse power flow prevention control are appropriately switched by the control unit 20 based on the detected power flow power, so that the control system is conventionally executed as a different control system. It is possible to realize demand control and reverse power flow prevention control in one control system.

In addition, since each of the demand control and the reverse power flow prevention control has a fail-safe function, even if an abnormality occurs in the load 40 in the field, the demand control and the reverse power flow prevention control can be reliably executed. It will be possible.

As described above, the power control system, the power control method, and the power control program according to the present invention automatically determine the operating area of reverse power flow prevention control by the power generation device that generates power by demand control and renewable energy, and stably supplies power. Can be realized.

1 Power control system 10 Power flow detection unit 20 Control unit 201 Switching judgment unit 202 Control switching unit 203 Demand setting unit 204 Power generation amount setting unit 205 Target value setting unit 206 Comparison unit 207 Adjustment unit 208 Output switching unit 30 Power generation system 301 Solar panel 302 Power converter 303 Power generation amount detection unit 304 Signal conversion unit 40 On-site load 60 Demand signal output unit 70 Power generation signal output unit 80 Demand guarantee unit 90 Power generation guarantee unit 100 Operation unit 101 Dial 102 Demand display unit 103 Target demand display unit 104 Lighting Display 110 Power branch

Claims (9)

A tidal current power detector that detects the tidal current power supplied from the commercial power system,
A demand signal output unit that outputs a demand signal whose load power consumption is a predetermined demand target value to the load, and a demand signal output unit.
A power generation system having a power generation device that generates electric power from renewable energy and a power converter that outputs the generated power generated by the power generation device, and a power generation system.
In a power control system including a power generation signal output unit that controls the amount of power generated by the power generation device and outputs a power generation signal to the power generation system to prevent reverse power flow of the generated power to the commercial power system.
It has a control unit including a demand signal output unit and an output switching unit that switches an output signal to be output to the power generation signal output unit based on the power flow power.
The control unit outputs the demand signal from the output switching unit to the demand signal output unit when the power flow power is equal to or higher than a predetermined threshold value, and when the power flow power is less than the predetermined threshold value. Is a power control system that outputs the power generation signal from the output switching unit to the power generation signal output unit. The output of the load is negatively controlled by the demand signal output from the demand signal output unit so that the difference between the power consumption and the demand target value becomes zero.
The power control system according to claim 1, wherein the power generation signal output from the power generation signal output unit performs positive control for increasing the output value of the generated power in proportion to the input value of the power consumption. The demand signal output unit is
The first proportional control that outputs a first demand signal to the load is executed so that the power consumption becomes less than the demand target value, and the load preset from the start of the first proportional control. 1 or 2 claim that after the delay time in consideration of the response delay time of the above has elapsed, the second proportional control for outputting the second demand signal corresponding to the change in the power consumption to the load is executed. The power control system described in. The demand setting unit that sets the demand target value is
It has a variable resistance whose resistance value changes with the rotation of the dial.
The power control system according to any one of claims 1 to 3, wherein the demand target value is set based on the resistance value of the variable resistor set by the rotation of the dial. It has a display unit that displays the deviation between the demand target value and the power consumption.
The power control system according to any one of claims 1 to 4, wherein the display unit includes a voltage dividing resistor and a voltage dividing circuit including a plurality of constant voltage diodes that light up at different operating voltages. It has a demand guarantee unit that sets a demand guarantee target value that is approximately 50 to 80% of the demand target value.
The demand guarantee unit outputs a fail-safe demand signal based on the demand guarantee target value to the load when the power flow power detection unit determines that the power flow power is not detected. 5. The power control system according to any one of 5. It has a power generation guarantee unit that sets an abnormal power flow power that is a lower limit threshold value of the power flow power that is set based on the power consumption of the load.
When it is determined that the tidal current power is less than the abnormal tidal current power, the power generation guarantee unit controls the power generation system to generate power that is approximately 2 to 5% of the maximum power generation power of the power generation system. The power control system according to any one of claims 1 to 6, which outputs a safe power generation signal. A tidal current power detector that detects the tidal current power supplied from the commercial power system,
A demand signal output unit that outputs a demand signal whose load power consumption is a predetermined demand target value to the load, and a demand signal output unit.
A power generation system having a power generation device that generates electric power from renewable energy and a power converter that outputs the generated power generated by the power generation device, and a power generation system.
A power generation signal output unit that controls the amount of power generated by the power generation device and outputs a power generation signal to the power generation system to prevent reverse power flow of the generated power to the commercial power system.
In a power control method of a power control system including a demand signal output unit and a control unit having an output switching unit for switching an output signal to be output to the power generation signal output unit based on the tidal current power.
A step of determining whether or not the tidal current power is equal to or higher than a predetermined threshold value, and
A step of outputting the demand signal from the output switching unit to the demand signal output unit when it is determined that the power flow power is equal to or higher than a predetermined threshold value.
A power control method comprising a step of outputting the power generation signal from the output switching unit to the power generation signal output unit when it is determined that the power flow power is less than a predetermined threshold value. A tidal current power detector that detects the tidal current power supplied from the commercial power system,
A demand signal output unit that outputs a demand signal whose load power consumption is a predetermined demand target value to the load, and a demand signal output unit.
A power generation system having a power generation device that generates electric power from renewable energy and a power converter that outputs the generated power generated by the power generation device, and a power generation system.
A power generation signal output unit that controls the amount of power generated by the power generation device and outputs a power generation signal to the power generation system to prevent reverse power flow of the generated power to the commercial power system.
A program executed by the control unit of a power control system including a demand signal output unit and a control unit having an output switching unit for switching an output signal output to the power generation signal output unit based on the tidal current power. hand,
A step of determining whether or not the tidal current power is equal to or higher than a predetermined threshold value, and
A step of outputting the demand signal from the output switching unit to the demand signal output unit when it is determined that the power flow power is equal to or higher than a predetermined threshold value.
A power control program including a step of outputting the power generation signal from the output switching unit to the power generation signal output unit when it is determined that the power flow power is less than a predetermined threshold value.

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