JP6263433B2 - Power supply system - Google Patents

Description

  The present invention relates to a power supply system that supplies power to a load facility from a power generation unit capable of constant control of received power.

  A power generation unit capable of constant control of received power is used as a means to cover the power consumption of a load facility on the premises with a generator in the premises while receiving power (commercial power) from an electric power company. In the received power constant control, the power supply path from the power company, the generator, and the load facility are connected, and the power (received power) supplied from the power company at the power receiving point is a predetermined value (for example, 0). By controlling the output power of the generator so as to become, it becomes possible to absorb the load fluctuation of the load facility by the generator.

  In such a power generation unit capable of constant control of received power, a technique for improving the operating rate of the generator is known (for example, Patent Document 1).

JP-A-10-224992

  Such a power generation unit capable of constant control of received power, that is, a current transformer (CT: Current Transformer) installed at a power receiving point, and a generator so that a measured value transformed by the current transformer becomes a predetermined value. A power generation unit in which a generator control unit that controls output is combined with a generator has high versatility, and is applied to load facilities for various purposes. For example, the power storage unit can be connected to the power generation unit, and the received power constant control can be performed including the power storage unit. The power storage unit is configured by, for example, a storage battery or the like, and charges the surplus power in the power supply path during the interconnected operation, and charges the power generated by the generator during the independent operation. The charged power can be output when necessary.

  However, in self-sustained operation, when the generator is controlled by the constant received power control, the generator's power generation state is determined by whether the constant received power control is set to the power purchase direction or the power sale direction, and the power purchase In the direction, the generator always stops generating power, and in the power selling direction, the generator always generates power at the rated value. Accordingly, the power storage unit always discharges to cover the power to the load facility in the power supply system in the power purchase direction, and always charges surplus power of the generator in the power sale direction. However, even in the power selling direction, if the capacity of the load facility exceeds the rating of the generator, the power storage unit is also discharged. As described above, in the self-sustaining operation, the moving direction of electric power is determined, and the generator and the power storage unit cannot be effectively used.

  In view of such a problem, the present invention can appropriately realize charging and discharging of a power storage unit in a self-sustained operation without wasting resources such as a current transformer and a generator control unit originally provided in the power generation unit. It aims at providing a simple power supply system.

In order to solve the above problems, a power supply system of the present invention is connected to a power supply path from an electric power company and a load facility, and a generator that supplies power to the load facility and at least the power supply path are inserted. , A generator current transformer that transforms the current value of the power supply path into a measured value, and a generator control that controls the output power of the generator so that the measured value transformed by the generator current transformer becomes a predetermined value And a power storage unit connected to the power provider side from the current transformer for the generator in the power supply path and capable of storing at least the power generated by the power generator during self-sustained operation, and a current transformer for the generator together with the power supply path additional control channel inserted through the vessel, energy storage unit has passed the control current in a direction to increase the power output of the generator so as to be charged, also in the direction in which the power storage unit to reduce the power output of the generator so as to be discharged Add supplying a control current Characterized in that it comprises a control unit, a.

  The maximum value of the control current may be the smaller of the power generation capacity of the generator and the inverter capacity of the power storage unit.

  The additional control path may be wound any number of times from 3 to 30 times around the penetration body of the generator current transformer.

  The additional control path is formed in a variable part that can be wound any number of times from 3 to 30 times and is variable in the number of turns in the through body of the current transformer for the generator. The control current may be controlled by changing the number of turns of the part.

  The additional control path may be provided with a variable resistor having a variable resistance value, and the additional control unit may control the control current by changing the resistance value of the variable resistor.

  According to the present invention, it is possible to appropriately realize charging / discharging of a power storage unit in a self-sustaining operation without wasting resources such as a current transformer and a generator control unit originally provided in the power generation unit.

It is explanatory drawing for demonstrating the electric power generation unit in which received electric power constant control is possible. It is explanatory drawing which showed schematic structure of the electric power supply system used as a premise. It is explanatory drawing for demonstrating control of the output electric power of a generator by an additional control part. It is explanatory drawing for demonstrating control of the output electric power of a generator by an additional control part. It is explanatory drawing for demonstrating the electric power supply system using an electrical storage unit. It is explanatory drawing which showed the schematic structure of the electric power supply system. It is a flowchart for demonstrating the flow of a process of an additional control part. It is explanatory drawing for demonstrating an additional control path. It is another explanatory view for explaining an additional control way.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. The dimensions, materials, and other specific numerical values shown in the embodiments are merely examples for facilitating the understanding of the invention, and do not limit the present invention unless otherwise specified. In the present specification and drawings, elements having substantially the same function and configuration are denoted by the same reference numerals, and redundant description is omitted, and elements not directly related to the present invention are not illustrated. To do.

  FIG. 1 is an explanatory diagram for explaining a power generation unit 10 capable of constant control of received power. As shown in FIG. 1, the power generation unit 10 is configured to include a generator 12, a generator current transformer 14, and a generator controller 16. The generator 12 is connected to a power supply path 20 from a power company and a load facility 22 arranged on the premises, converts other energy into electric energy to generate electric power, and generates the generated electric power to the load facility 22. To supply. As such a generator, various other devices such as an electric motor and a fuel cell can be applied. In the current transformer 14 for generator, the power supply path 20 is inserted (clamped) into a through body (iron core, core) in which a primary winding is arranged at a power reception point, and the current value of the power supply path 20 is transformed into a measured value. To the generator control unit 16. The generator control unit 16 is constituted by a CPU and a DSP, and the generator is set so that the measured value transformed by the generator current transformer 14 becomes a predetermined value (for example, 0) (so that the power receiving point is leveled). 12 output power is feedback controlled.

  Thus, in the power generation unit 10, the generator control unit 16 determines that the measured value transformed by the generator current transformer 14, that is, the current value flowing through the power receiving point is a predetermined value (assumed to be 0 here). Since the output power of the generator 12 is controlled so that the load fluctuation occurs in the load facility 22 as in the power transition shown in FIG. 1A, the power transition shown in FIG. As described above, the power corresponding to the fluctuation can be output to the generator 12. Thus, the power fluctuation at the power receiving point is theoretically maintained at 0 as in the power transition shown in FIG. However, in the present embodiment, for convenience of explanation, the power (current) at the power receiving point is described as 0. However, from the viewpoint of system protection such as prevention of reverse power flow due to load fluctuations, power is actually supplied from the power supply path 20. As (power purchase), a significant value is set as the predetermined value. The predetermined value is determined based on the power generation capacity of the generator 12 or the like.

  In the present embodiment, existing resources such as the generator current transformer 14 and the generator control unit 16 included in the power generation unit 10 capable of constant control of received power as described above are not wasted (modified) as they are. It is premised on a technique for effectively using and supplying power to the load facility 22 appropriately. Below, the electric power supply system 100 used as the premise of such this embodiment is demonstrated.

(Prerequisite technology: power supply system 100)
FIG. 2 is an explanatory diagram showing a schematic configuration of the power supply system 100 as a premise. As shown in FIG. 2, the power supply system 100 includes a power generation unit 10 (a generator 12, a generator current transformer 14, a generator control unit 16) and an additional control unit 110. The power generation unit 10 is the same as that described with reference to FIG. The additional control unit 110 is configured by a CPU and a DSP. Along with the power supply path 20, the additional control unit 110 supplies a control current to the additional control path 112 inserted through the penetrating body of the generator current transformer 14, and generates power through the generator control unit 16. The output power of the machine 12 is indirectly controlled.

  3 and 4 are explanatory diagrams for explaining the control of the output power of the generator 12 by the additional control unit 110. Here, the power transition of (a), (b), (c) shown in FIG. 3 and FIG. 4 is the power transition in the direction of (a), (b), (c) of FIG. And the current transition of (d) shown in FIG. 4 is a current transition of the direction of (d) of FIG.

  When the additional control unit 110 causes a positive current as shown in FIG. 3D to flow in the additional control path 112 in the direction of FIG. 2D, a current corresponding to the amount added in the generator current transformer 14 is obtained. The generator control unit 16 recognizes that the current flow is due to power fluctuation at the power receiving point. Then, since the generator control unit 16 controls the output power of the generator 12 so that the measurement value transformed by the generator current transformer 14 becomes a predetermined value, the power output of the generator 12 is increased. Therefore, as shown in FIG. 3B, the power output of the generator 12 is increased while the additional control unit 110 is passing current, and the power equal to the increased amount (ΔP) is, for example, shown in FIG. As shown in c), the electric power is output to the power supply path 20 through the power receiving point.

  Further, when the additional control unit 110 causes a negative current as shown in FIG. 4D to flow in the additional control path 112 in the direction of FIG. 2D, the amount added to the generator current transformer 14 is increased. Thus, the generator control unit 16 recognizes that the current flow is caused by power fluctuation at the power receiving point, as in FIG. Then, the generator control unit 16 controls the output power of the generator 12 so that the measurement value transformed by the generator current transformer 14 becomes a predetermined value, so that the power output of the generator 12 is reduced. Therefore, as shown in FIG. 4B, while the additional control unit 110 is passing current, the power output of the generator 12 is lowered, and the power equal to the lowered amount (ΔP) is, for example, shown in FIG. As shown in c), it is replenished from the power supply path 20 through the power receiving point.

  Thus, while the existing power generation unit 10 is effectively used as it is without removing the generator current transformer 14 and the generator control section 16, the additional control section 110 passes through the generator current transformer 14. By causing a current to flow through the additional control path 112 inserted into the generator, the generator control unit 16 is made to recognize as if the current of the power supply path 20 has changed, and the output power of the generator 12 is individually controlled. Is possible.

  The output power control of the power generation unit 10 using the additional control unit 110 as described above can be applied to various uses. Hereinafter, an example in which a power storage unit is used as an example of the power generation unit 10 using the additional control unit 110 will be described.

  FIG. 5 is an explanatory diagram for explaining a power supply system using the power storage unit 40. This embodiment is different from FIG. 1 in that a power storage unit 40 is provided on the premises. The power storage unit 40 is constituted by, for example, a storage battery or the like, and charges the surplus power in the power supply path 20 at the time of the grid operation, and charges the power generated by the generator 12 at the time of the independent operation. Further, the power storage unit 40 can output the charged power when necessary.

  In this way, when the power storage unit 40 capable of storing electricity is applied to the power generation unit 10, as shown in FIG. 5, the power supply path 20, the generator 12, the power storage unit 40, and the load facility 22 are connected to each other. It can be considered that the power supply path 20 on the electric power provider side is inserted into the penetrating body of the current transformer 14 from the connection point. In the configuration of FIG. 5, no problem occurs while the interconnection operation is being performed, but a problem may occur when the interconnection is disconnected by the switch 42 and the operation state is switched to the independent operation. For example, in the configuration as shown in FIG. 5, when the generator 12 is controlled so that the received power becomes a predetermined value in the self-sustained operation, the predetermined value is positive or negative, that is, the received power constant control is set in the power purchase direction. The power generation state of the generator 12 is determined depending on whether it is set to the power selling direction, the power generation of the generator 12 is always stopped in the power purchase direction, and the generator 12 always generates power at the rated power in the power selling direction. . Accordingly, the power storage unit 40 always discharges to cover the power to the load equipment 22 in the power supply system 100 in the power purchase direction, and always charges surplus power of the generator 12 in the power sale direction. However, when the capacity of the load facility 22 exceeds the rating of the generator even in the power selling direction, the power storage unit 40 is also discharged. Thus, in the self-sustained operation, the moving direction of electric power is determined, and the generator 12 and the power storage unit 40 cannot be effectively used.

(Power supply system 200)
In this embodiment, even in such a situation, the load facility 22, the power storage unit 40, and the generator 12 are comprehensively regarded as one system, and the power fluctuations with respect to the other systems are leveled, and the power storage unit 40 The purpose is to realize charging and discharging appropriately.

  FIG. 6 is an explanatory diagram showing a schematic configuration of the power supply system 200. As shown in FIG. 6, the power supply system 200 includes a power generation unit 10 (a generator 12, a current transformer 14 for a generator, a generator control unit 16), a power storage unit 40, and an additional control unit 110. Composed.

  The power generation unit 10 is the same as that described with reference to FIG. The power storage unit 40 is connected to the power provider side from the generator current transformer 14 in the power supply path 20. Further, in the generator current transformer 14, the additional control path 112 as well as the power supply path 20 is inserted into the through-hole of the generator current transformer 14, as in the presupposed technology. In the configuration of FIG. 6, unlike FIG. 5, it can be understood that the power supply path 20 between the power storage unit 40 and the generator 12 is inserted through the through-passage of the generator current transformer 14.

  By the way, in the power generation unit 10, the normal operation of the generator current transformer 14 is confirmed when the generator 12 is started up. Specifically, at the time of start-up, the generator 12 itself consumes power, and the generator control unit 16 detects this power consumption through the generator current transformer 14, thereby generating the generator current transformer. It is understood that there is no abnormality (for example, disconnection) in the generator 14, and the generator 12 is normally activated. Here, the power supply path 20 is inserted into the penetrating body of the current transformer 14 for the generator, so that the power supply path can be used when the generator 12 is started up even in a self-sustaining operation where power is not supplied from the power company. Since power is supplied from the power storage unit 40 to the generator 12 through 20 and the power can be detected through the generator current transformer 14, the generator 12 cannot be started up due to the failure of the generator current transformer 14. It is possible to avoid such a situation.

  Then, the additional control unit 110 controls the output power of the generator 12 by causing a control current to flow through the additional control path 112 as in the premise technology. However, in the present embodiment, the additional control unit 110 causes the control current to flow so that the power storage unit 40 can repeat charging and discharging according to the state of charge of the power storage unit 40 (so that charge and discharge can be performed).

  FIG. 7 is a flowchart for explaining the flow of processing of the addition control unit 110. Such a flowchart is executed as interrupt processing at predetermined time intervals. First, the additional control unit 110 derives a charged state of the power storage unit 40 (S350). The state of charge indicates the charge capacity as a ratio (%) to full charge, and there are a method of deriving from the output voltage, output current and storage battery temperature, and a method of deriving from the discharge power and charge power history of the power storage unit. Since this derivation method is an existing technique, detailed description thereof is omitted here.

  Next, the additional control unit 110 determines whether or not the derived state of charge is less than a first threshold (for example, 30%) (S352). If the state of charge is less than the first threshold (YES in S352), a positive control current (in the direction of the arrow in FIG. 6) is passed through the additional control path 112 so that the power storage unit 40 can be charged (S354). If the state of charge is not less than the first threshold (NO in S352), the additional control unit 110 determines whether or not the derived state of charge is greater than or equal to the second threshold (for example, 95%) (S356). If the state of charge is equal to or greater than the second threshold (YES in S356), a negative control current (in the reverse direction of the arrow in FIG. 6) is supplied to the additional control path 112 so that the power storage unit 40 can be discharged (S358). . If the state of charge is not greater than or equal to the second threshold (NO in S356), the direction of the control current up to the previous time is maintained.

  Subsequently, the additional control unit 110 determines a current value of the control current. Specifically, the additional control unit 110 determines whether or not the charging mode is the speed priority mode (S360), and if it is the speed priority mode (YES in S360), sets the maximum value as the control current (S362). . If it is not the speed priority mode, that is, if it is the efficiency priority mode (NO in S360), an adjustment value is set as the control current (S364).

  Here, the charging mode has an efficiency priority mode and a speed priority mode. The former is a quick operation such as during an interconnected operation and a self-sustained operation with sufficient charging time, and the latter is a quick operation during a power failure or emergency processing. It is used during self-sustaining operation that needs to be recharged. The maximum value of the control current is the smaller of the power generation capacity of the generator 12 and the inverter capacity of the power storage unit 40 when a positive control current is flowing (in a charged state), and the negative control current Is flowing (in a discharged state), the inverter capacity of the power storage unit 40. The adjustment value of the control current is a value equal to or less than the maximum value, and is a value that increases one or both of the charging efficiency of the power storage unit 40 and the power generation efficiency of the generator 12.

  However, as will be described later, in order to adjust the scale of the current value in the generator current transformer 14, the additional control path 112 is wound around the penetrator itself of the generator current transformer 14 a plurality of times (for example, five times). In this case, since the maximum value of the control current corresponds to a value that flows through the through-hole after winding, the value of the control current controlled by the additional control unit 110 is actually the maximum value of the control current / the number of turns.

  In this way, by switching the direction of the control current according to the state of charge, even in the case of independent operation, power interchange between the load facility 22, the power storage unit 40, and the generator 12 is substantially completed. In addition, when the load facility 22, the power storage unit 40, and the generator 12 are viewed as a single system, it is possible to appropriately realize charging and discharging of the power storage unit 40 while leveling power fluctuations with respect to other systems. .

(Additional control path 112)
However, in the present embodiment, since the power supply path 20 and the additional control path 112 are both inserted through the penetration body of the generator current transformer 14, the generator 12 is controlled by the control current from the additional control unit 110. In this case, it is necessary to make the change width of the current received by the generator current transformer 14 by the control current equal to the change width of the current received by the generator current transformer 14 by the power supply path 20. In order to increase the change width of the current received by the generator current transformer 14, the following means can be considered.
(1) The voltage value V applied to the additional control path 112 is increased.
(2) The resistance value R of the additional control path 112 is reduced.
(3) The additional control path 112 is wound around the penetration body of the generator current transformer 14 a plurality of times.

However, either means (1) or (2) is not practical because it involves energy consumption due to Joule heat (V ² / R) in the additional control path 112. Further, in the means of (1) and (2), the additional control unit 110 itself must have an ability to generate a current equivalent to the current supplied from the power supply path 20 in the first place.

  Therefore, here, a means for winding the additional control path 112 of (3) around the penetrating body of the generator current transformer 14 a plurality of times will be examined. In this way, by winding the additional control path 112 around the penetration body of the generator current transformer 14 a plurality of times, the generator current transformer 14 is controlled by the control current while suppressing energy consumption due to Joule heat. The change width of the received current and the scale of the change width of the current received by the generator current transformer 14 through the power supply path 20 can be matched.

  FIG. 8 is an explanatory diagram for explaining the additional control path 112. The additional control path 112 is wound, for example, five times so as to be inserted into the through hole 14b of the through body 14a of the current transformer 14 for generator. Thus, with respect to the current in the power supply path 20, assuming that the originally required control current is I and the number of turns is N, it is sufficient that the additional control unit 110 can control the current of I / N.

  The number of turns of the additional control path 112 is 5 for convenience of explanation, but it is 3 to 30 times, more preferably 5 to 10 times. Here, the number of windings is set to 3 times or more because if the number of windings is 1 or 2 after all, the current itself flowing through the additional control path 112 becomes large and the consumption of Joule heat cannot be suppressed. is there. In addition, the number of windings is set to 30 or less because if the number of windings exceeds 30, the noise from the outside is amplified by the number of windings and then rides on the control current, so that the control current is easily affected by the noise. .

As a reference, for example, the following three may be considered as causes of noise.
(A) Influence of electromotive force due to electromagnetic induction: If the number of turns is N, the current flowing through the power supply path 20 is I ₀ , and the radius of the penetrating body 14a is r, the additional control path 112 has an electromotive force ΔV = N / 2πr × dI ₀ / dt is induced.
(B) Influence of surge noise due to electromagnetic joining: When the wiring of the power supply path 20 and the wiring of the additional control path 112 are close to each other, the surge noise flowing through the power supply path 20 is transmitted to the additional control path 112 by the electromagnetic contact path. .
(C) Influence of radiated electromagnetic field immunity: Radio waves from amateur radios or mobile phones ride on the additional control path 112.

By the way, although the additional control part 110 has a function which controls a control current, the control precision by a control current may be inferior for the following reasons.
(I) As a voltage source to be applied to the additional control path 112, only a constant voltage source, for example, a commercial 100V can be used.
(Ii) The variable width of the control current of the additional control unit 110 is small in the first place.
(Iii) The resolution of the control current is low in the first place.

  Therefore, in the present embodiment, by making the number of turns or the resistance value of the additional control path 112 variable, it is possible to change the variable width of the control current or change the resolution regardless of whether it is a constant voltage source. .

  FIG. 9 is another explanatory diagram for explaining the additional control path 112. In FIG. 9A, the additional control path 112 is wound around the through body 14a five times so as to be inserted into the through hole 14b of the through body 14a of the generator current transformer 14. . In the variable portion 112a of the additional control path 112, a contact is provided for each turn of the winding, and the number of windings is varied depending on the connection mode of the contact. Further, as shown in FIG. 9B, by providing the additional control path 112 with a variable resistance 112b having a variable resistance value, the resistance value R of the additional control path 112 is changed, and the control current (V / R) is variable. It can also be made. The change of the variable part 112a and the variable resistor 112b may be automatically performed from the additional control unit 110, or may be manually performed according to the power usage mode.

  In this way, by varying the control current independently of the control current variable capability of the additional control unit 110, the control current variable width can be increased, the control current variable capability of the additional control unit 110, the variable portion 112a, etc. It can be expanded to the range multiplied by the variable ability. In addition, since the resolution of the control current of the additional control unit 110 can be varied by the variable portion 112a or the like, it is possible to deal with control that requires resolution.

  As described above, the power supply systems 100 and 200 enable constant control of received power without wasting resources such as the generator current transformer 14 and the generator control unit 16 originally provided in the power generation unit 10. It is possible to appropriately supply power from the power generation unit 10 to the load facility 22.

  In addition, the power supply system 200 can start up the generator 12 normally even during a self-sustained operation, and can appropriately realize charging / discharging of the power storage unit 40.

  As mentioned above, although preferred embodiment of this invention was described referring an accompanying drawing, it cannot be overemphasized that this invention is not limited to this embodiment. It will be apparent to those skilled in the art that various changes and modifications can be made within the scope of the claims, and these are naturally within the technical scope of the present invention. Understood.

  Note that the steps described as processing of the additional control unit 110 in this specification do not necessarily have to be processed in time series in the order described in the flowchart, and include processing in parallel or subroutines, The processing after priority mode determination S360 may not be performed.

  The present invention can be used for a power supply system that supplies power to a load facility from a power generation unit capable of constant control of received power.

DESCRIPTION OF SYMBOLS 10 Power generation unit 12 Generator 14 Current transformer 14a Generator 16 Generator control part 20 Power supply path 22 Load equipment 40 Power storage unit 100, 200 Power supply system 110 Additional control part 112 Additional control path 112a Variable part 112b Variable Resistance 120 External current transformer

Claims (5)

A generator connected to a power supply path and a load facility from an electric power company and supplying power to the load facility;
At least the power supply path is inserted, and a current transformer for a generator that transforms the current value of the power supply path into a measured value;
A generator control unit for controlling the output power of the generator so that the measurement value transformed by the generator current transformer becomes a predetermined value;
A power storage unit connected to the power provider side from the generator current transformer in the power supply path, and capable of storing power generated by the generator at least during self-sustaining operation;
Additional control channel inserted through the current transformer for the power generator with the power supply path, wherein the energy storage unit has passed the control current in a direction to increase the power output of the generator so as to be charged, also, the accumulating unit An additional control unit that causes a control current to flow in a direction to reduce the power output of the generator so that it can be discharged ;
A power supply system comprising:   The power supply system according to claim 1, wherein the maximum value of the control current is the smaller one of the power generation capacity of the generator and the inverter capacity of the power storage unit.   3. The power supply system according to claim 1, wherein the additional control path is wound any number of 3 to 30 times around the penetrating body of the generator current transformer. The additional control path is wound around the generator current transformer through 3 to 30 times, any number of times, and a variable part is formed to make the number of turns variable,
The power supply system according to claim 1, wherein the additional control unit controls the control current by changing the number of turns of the variable part. The additional control path is provided with a variable resistor having a variable resistance value,
The power supply system according to claim 1, wherein the additional control unit controls a control current by changing a resistance value of the variable resistor.

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