JP2007178326A - Method of measuring electric power and generating facility - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of measuring correct electric power without correcting reinstallation, even if an attaching direction and a connection position of a current transformer are not correct, and also to provide a generating facility. <P>SOLUTION: The method of measuring the electric power comprises processes of: inspecting installation conditions of the current transformers 21, 22; correcting the current values detected with the current transformers 21, 22 on the basis of inspection results; and calculating the electric power on the basis of corrected current values. The generating facility 1 comprises: the current transformer 21 for detecting the current of a cable 96R; the current transformer 22 for detecting the current of a cable 96T; a voltage detector 23 for detecting the voltages of the cables 96R, 96T; a power generation part 11 for generating the electric power supplied to electric power load 99; and a control part 15 for calculating electric power values, on the basis of the detected current values and voltage values. The generating facility 1 uses the method of measuring electric power. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a power measurement method and a power generation device, and more particularly to a power measurement method and a power generation device capable of measuring correct power without re-installation even if there is an error in the mounting direction or connection position of the current transformer. .

  As a means for measuring the AC power supplied to the power demand, there is one that detects an interphase voltage and a phase current and obtains a product of these. When there are a plurality of interphase voltages and phase currents, the total power is obtained by obtaining the sum of the power values of the respective phases. In general, a current transformer is used for current measurement, and a transformer is used for voltage measurement. The current transformer forms a magnetic flux as an exciting current of a primary current (current flowing through a load) via an iron core or the like, and measures a current flowing through the secondary side (measurement side). The current transformer can easily measure from a large current to a small current by appropriately setting the winding ratio between the primary side and the secondary side.

  However, since the current transformer detects the current using the magnetic flux generated by the exciting current, if the mounting direction with respect to the current flow direction is wrong, it is recognized that the current flows in the direction opposite to the direction in which the current actually flows. Resulting in. Normally, when installing a current transformer, work is done after confirming the mounting direction and connection position, but depending on the experience of the operator, the power generation device may be constructed by mistakenly in the mounting direction and / or connection position. It can happen. If the current transformer is reconnected after the power generation device is constructed, work costs will be incurred.

  In view of the above-described problems, the present invention has an object to provide a power measurement method and a power generation apparatus that can measure correct power without re-installation even if there is an error in the mounting direction or connection position of the current transformer. To do.

  In order to achieve the above object, the power measuring method according to the first aspect of the present invention measures AC power using current transformers 21 and 22 (see, for example, FIG. 1) as shown in FIG. 3, for example. A method for measuring power; a step of inspecting the installation status of the current transformers 21 and 22 (S101); a step of correcting the current value detected by the current transformers 21 and 22 based on the result of the inspection (S104); A step of calculating power based on the corrected current value (S105).

  If comprised in this way, even if it is a case where there exists an error in the attachment direction and connection position of a current transformer, correct electric power can be measured, without installing a current transformer again. Moreover, since the process which inspects the installation condition of a current transformer is provided, it can be detected whether the malfunction has arisen in the electric power measurement apparatus.

  Further, the power measuring method according to the invention of claim 2 is the power measuring method of claim 1, wherein the step of inspecting changes the magnitude of the current detected by the current transformer, And a step of confirming whether or not there is a change in the detected value of the current transformer in accordance with a change in the magnitude of the current.

  With this configuration, the current transformer detects the change in the detected value of the current transformer according to the change in the current magnitude as the current magnitude detected by the current transformer changes. It is possible to determine whether the mounting direction and connection position of the device are correct.

  Further, the power measurement method according to the invention of claim 3 is the power measurement method of claim 1 or claim 2, wherein the power to be measured is from a commercial power source linked to the power generated by the fuel cell. This is the power supplied.

  If comprised in this way, since the electric power supplied from the commercial power source linked with the electric power generated with the fuel cell is measured, the power consumption based on a commercial power source can be measured. Moreover, when the measured electric power value is sent to the control part which controls a fuel cell, the output of a fuel cell can be controlled based on the measured electric power value.

  Further, in the power measurement method according to any one of claims 1 to 3, the inspection step may be performed every predetermined time.

  If comprised in this way, when a malfunction arises in the system which is measuring electric power, a malfunction can be discovered at least within a predetermined time, and a countermeasure can be taken.

  In order to achieve the above object, a power generator according to a fourth aspect of the present invention includes, for example, a first cable 96R connected to power loads 12 and 99 that are supplied with AC power, as shown in FIG. A first current detector 21 for detecting a flowing current; a second current detector 22 for detecting a current flowing through a second cable 96T connected to the power loads 12, 99; and a voltage of the first cable 96R And a voltage detector 23 that detects the voltage of the second cable 96T; a power generation unit 11 that generates power to be supplied to the power load 99; and a first current that inputs a current value detected by the first current detector 21 Input terminals 15Ra and 15Rb, second current input terminals 15Ta and 15Tb for inputting a current value detected by the second current detector 22, and a voltage input terminal 15Vr for inputting a voltage value detected by the voltage detector 23, 5Vt, 15Vn, and the power value is calculated based on the current value detected by the first current detector 21, the current value detected by the second current detector 22, and the voltage value detected by the voltage detector 23. The control device 15 changes the magnitude of the current flowing through the first cable 96R, and the magnitude and change of the current values of the first current detector 21 and the second current detector 22 And the magnitude of the current flowing through the second cable 96T is changed to check the magnitude of the current values of the first current detector 21 and the second current detector 22 and whether or not there is a change. Thus, it is determined that the installation direction and the installation position of the first current detector 21 and the second current detector 22 are appropriate, and the power value is calculated by correcting the detected current value when it is not appropriate. It is configured.

  With this configuration, the control device changes the magnitude of the current flowing through the first cable to check the magnitude of the current values of the first current detector and the second current detector and whether or not there is a change. And the first current detector by changing the magnitude of the current flowing through the second cable to check the magnitude of the current value of the first current detector and the second current detector and whether or not there is a change. Since the power direction is calculated by correcting the current value detected when the installation direction and the installation position of the second current detector are not appropriate and correcting the current value detected when it is not appropriate, there is an error in the installation direction and connection position of the current transformer. Even if there is, correct power can be measured without re-installing the current transformer. Further, when determining the appropriate installation direction and installation position of the first current detector and the second current detector, it is possible to detect whether or not a problem has occurred in the power measurement device.

  The power generator according to the invention described in claim 5 is the power generator 1 according to claim 4 (see, for example, FIG. 1), wherein the current detectors 21, 22 (see, for example, FIG. 1) are clamp-type changers. Consists of a flow device.

  If comprised in this way, an electric current can be detected by a simple means.

  Further, in the power generation apparatus according to the invention described in claim 6, for example, as illustrated in FIG. 1, in the power generation apparatus 1 according to claim 4 or 5, one of the power loads 12 and 99 is the power generation unit 11. The first cable 96R has a first switch 25 for supplying and shutting off current to the accessory 12, and the second cable 96T for supplying current to the accessory 12. A second switch 26 that cuts off; switching the first switch 25 changes the magnitude of the current flowing through the first cable 96R, and switching the second switch 26 changes the second cable 96T. It is comprised so that the magnitude | size of the flowing electric current may be changed.

  With this configuration, since one of the power loads is composed of an auxiliary device related to the operation of the fuel cell, the current flowing through the first and second cables without affecting the power load that is put to practical use. The size of can be changed. In addition, it is possible to determine the appropriateness of the installation direction and installation position of the current detector by simple means.

  The power generator according to claim 7 is the power generator according to any one of claims 4 to 6, wherein the power generator 11 (see, for example, FIG. 1) is formed of a fuel cell. Yes.

  If comprised in this way, since the electric power generation part is comprised with the fuel cell, the electric power generating apparatus which contributes to carbon dioxide emission suppression can be constructed | assembled.

  According to the power measurement method of the present invention, the step of inspecting the installation status of the current transformer, the step of correcting the current value detected by the current transformer based on the inspection result, and the corrected current value And the step of calculating the power, the correct power can be measured without re-installing the current transformer even if there is an error in the mounting direction or connection position of the current transformer. In addition, it is possible to detect whether or not a failure has occurred in the power measuring device by the step of inspecting the installation state of the current transformer.

  Further, according to the power generation device according to the present invention, the control device changes the magnitude of the current flowing through the first cable to change the magnitudes of the current values of the first current detector and the second current detector, and By inspecting whether there is a change and changing the magnitude of the current flowing through the second cable to check the magnitude of the current value of the first current detector and the second current detector and whether there is a change The installation direction of the current transformer is determined because the installation direction and installation position of the first current detector and the second current detector are judged appropriate, and the detected current value is corrected to calculate the power value. Even if there is an error in the connection position, correct power can be measured without re-installing the current transformer. Further, when determining the appropriate installation direction and installation position of the first current detector and the second current detector, it is possible to detect whether or not a problem has occurred in the power measurement device.

  Embodiments of the present invention will be described below with reference to the drawings. In each figure, the same or corresponding devices are denoted by the same or similar reference numerals, and redundant description is omitted. In FIG. 1, a broken line represents a control signal.

  First, with reference to FIG. 1, the structure of the electric power generating apparatus 1 which concerns on embodiment of this invention is demonstrated. FIG. 1 is a system diagram illustrating a power generator 1 according to an embodiment of the present invention. The power generation apparatus 1 includes a power generation system 10 that is a private power generation apparatus, a current transformer 21 as a first current detector that detects a current received from a commercial power supply 98, and a current transformer 22 as a second current detector. And a transformer 23 as a voltage detector that detects a voltage received from the commercial power source 98. The power generation system 10 includes a fuel cell 11 as a power generation unit, auxiliary machinery 12 necessary for operation of the fuel cell 11, an inverter 13 that converts DC power generated by the fuel cell 11 into AC power, A control unit 14 that controls operation and a power detection unit 15 that detects power based on the current value detected by the current transformers 21 and 22 and the voltage value detected by the transformer 23 are provided.

  The fuel cell 11 introduces a reformed gas rich in hydrogen and an oxidant gas containing oxygen, generates electric power by an electrochemical reaction between hydrogen in the reformed gas and oxygen in the oxidant gas, and generates water and heat. Is a device that generates The fuel cell 11 is typically a polymer electrolyte fuel cell. The fuel cell 11 includes an anode part for introducing a reformed gas, a cathode part for introducing an oxidant gas, and a cooling part for removing heat generated by an electrochemical reaction. The fuel cell 11 is typically formed of a single layer formed by sandwiching a solid polymer membrane between an anode part and a cathode part, and is formed by laminating these layers. The reformed gas rich in hydrogen is a gas supplied to the fuel cell 11 containing hydrogen in an amount of 40% by volume or more, typically about 70 to 80% by volume. The hydrogen concentration in the reformed gas may be 80% by volume or more, that is, any concentration that allows power generation by an electrochemical reaction with oxygen in the oxidant gas when supplied to the fuel cell 11.

  The reformed gas supplied to the fuel cell 11 is generated by a reformer 12 </ b> A that is one of the auxiliary machines 12. The reformer 12A is typically configured to generate a reformed gas in which the raw material fuel is reformed by introducing and heating a hydrocarbon-based raw material fuel and process water. The power generation system 10 typically includes a blower 12B for supplying an oxidant gas (typically air) to the fuel cell 11 as auxiliary equipment other than the reformer 12A, a cooling unit for the fuel cell 11, and A cooling water pump 12C that circulates cooling water between a hot water storage tank that stores heat taken from the fuel cell 11, a hot water supply pump 12D that supplies hot water in the hot water storage tank toward a hot water supply load (not shown), and a hot water supply load And a heater 12E that supplementarily heats the hot water fed to (not shown).

  The inverter 13 is electrically connected to the fuel cell 11. The fuel cell 11 generates DC power because of its power generation principle. Since electric appliances that are widely spread in general operate by receiving supply of AC power, DC power generated by the fuel cell 11 is converted into AC power by the inverter 13. The inverter 13 may include a grid protection device that protects the power generation system 10 when linked to the grid power supplied from the commercial power source. In addition, the inverter 13 may be configured to control connection to the system power when the power generated by the fuel cell 11 is about to flow back to the system power when the reverse power flow is not allowed.

  The control unit 14 is configured to control the start and stop of the fuel cell 11, the auxiliary machinery 12, and the inverter 13, and output adjustment based on the power value calculated by the power detection unit 15. The control in the control unit 14 is typically performed such that the output of the fuel cell 11 covers the demand for electric power load within the range of the rated output.

  The power detector 15 includes R-phase ports 15Ra and 15Rb serving as first current input terminals connected to the current transformer 21 via electric wires, and a second current input terminal connected to the current transformer 22 via electric wires. T-phase ports 15Ta and 15Tb as voltage terminals, and voltage ports 15Vr, 15Vn and 15Vt as voltage input terminals connected to the transformer 23 via electric wires. Further, the power detection unit 15 has a calculation function capable of calculating a power value based on the current value detected by the current transformers 21 and 22 and the voltage value detected by the transformer 23. Typically, the power value is calculated as a product of a current value, a voltage value, and a predetermined power factor. The calculated power value is sent to the control unit 14. The power detection unit 15 and the control unit 14 constitute a control device 16.

  The power generation system 10 is linked to the grid power supplied from the commercial power source 98. The commercial power supply 98 connected to the power generation system 10 is typically single-phase, three-wire AC power. The three lines include an R-phase line 96R as a first cable, a T-phase line 96T as a second cable, and an N-phase line 96N for grounding. The voltage between the R-phase line 96R and the N-phase line 96N and the voltage (effective value) between the T-phase line 96T and the N-phase line 96N are 100 V, respectively. The voltage between is 200V.

  The power generation system 10 is connected to a commercial power supply 98 via a relay 95, and the auxiliary machinery 12, the inverter 13, the control unit 14, and the power detection unit 15 constituting the power generation system 10 are each supplied with system power. It is configured to be able to. The heater 12E of the auxiliary machinery 12 is typically divided into a heater 12Er that is supplied with current from the R-phase line 96R and a heater 12Et that is supplied with current from the T-phase line 96T. The inverter 13 is separately connected to the R-phase line 96R, the T-phase line 96T, and the N-phase line 96N, and the electric power generated by the fuel cell 11 and converted into alternating current (hereinafter referred to as “generated electric power”) is used as electric power. It is configured to be able to transmit power to the load 99 and, if permitted, to the commercial power source 98. The electric power load 99 is an electric device that consumes electric power, and operates by receiving system power and generated power. For example, a refrigerator or a washing machine corresponds to the power load 99 in the case of a general household. The power load 99 is connected to the secondary side of the relay 95 as in the power generation system 10.

  The current transformer 21 is typically a clamp-type current transformer. The current transformer 21 is configured so that an electric wire for measuring an alternating current is sandwiched between two swinging arms from above the insulation coating, and an electromotive force obtained by electromagnetic induction action is taken out. The current can be detected without removing or removing it. The current transformer 22 is configured in the same manner as the current transformer 21. The current transformer 21 is disposed on the R phase line 96 </ b> R between the power generation system 10 and the power load 99 and the relay 95. The current transformer 22 is disposed on a T-phase line 96T between the power generation system 10 and the power load 99 and the relay 95. The current transformer 21 is connected to the R-phase ports 15Ra and 15Rb of the power detection unit 15 via electric wires. The current transformer 22 is connected to the T-phase ports 15Ta and 15Tb of the power detection unit 15 via electric wires. Since the current transformers 21 and 22 have directionality, they are connected to the corresponding ports 15Ra, 15Rb, 15Ta, and 15Tb.

  The transformer 23 has three wires on both the primary side and the secondary side. The three electric wires on the primary side of the transformer 23 are connected to the R-phase line 96R, the T-phase line 96T, and the N-phase line 96N between the power generation system 10 and the power load 99 and the relay 95, respectively. Three wires on the secondary side of the transformer 23 are connected to the power detection unit 15, and the wires corresponding to the wires connected to the R-phase wire 96R on the primary side are connected to the voltage port 15Vr and the T-phase wire 96T. An electric wire corresponding to the connected electric wire is connected to the voltage port 15Vt, and an electric wire corresponding to the electric wire connected to the N-phase line 96N is connected to the voltage port 15Vn. The transformer 23 is configured to detect the RN voltage between the R phase line 96R and the N phase line 96N and the TN voltage between the T phase line 96T and the N phase line 96N. Has been.

  Of the auxiliary machines 12 of the power generation system 10, typically, a switch 25 as a first switch is disposed on the R-phase line 96R immediately upstream of the heater 12E. A switch 26 as a second switch is disposed on the T-phase line 96T immediately upstream of the heater 12E. The switches 25 and 26 are typically a-contact electromagnetic relays, but may be devices that open and close electrical circuits other than the relays. The switches 25 and 26 are electrically connected to the control unit 14, and are configured such that the control unit 14 controls the opening and closing of the electric circuit. The immediate upstream of the heater 12E means that when a switch is disposed there, whether or not the heater 12E is energized can be changed by turning the switch on / off. This position has no effect.

  In the power generation apparatus 1 described above, the output of the fuel cell 11 is controlled by the control unit 14 so that the power value calculated by the power detection unit 15 is within a predetermined range. That is, since the power detected by the power detection unit 15 is system power (when the generated power flows in reverse, the value of the generated power flowing in reverse flow is detected), the consumer is detected by the power detection unit 15. That means you have purchased the power for the minute. Therefore, the control unit 14 controls the output of the fuel cell 11 so that the purchased power is reduced as much as possible and the power generation amount in the fuel cell 11 is not excessively increased in order to prevent the reverse power flow to the commercial power source 98. To do. The output of the fuel cell 11 is typically controlled by controlling the amount of reformed gas generated by the reformer 12A, the flow rate of the oxidant gas supplied to the fuel cell 11 by the blower 12B, and the like. .

  The power value calculated by the power detector 15 is the sum of the product of the current detected by the current transformer 21 and the RN voltage and the product of the current detected by the current transformer 22 and the TN voltage. Desired. Since the current transformers 21 and 22 have directionality as described above, the power detection unit 15 detects a correct power value if the mounting direction and installation position do not correspond to each port connected to the power detection unit 15. It is not possible to detect the power value different from the actual value, or it may be misunderstood that the current is a reverse power flow although it is actually a reverse power flow. Usually, the current transformers 21 and 22 are installed with considerable care so that there is no error. However, the installation direction and installation position may be incorrect for some reason. If the current transformers 21 and 22 are mistakenly installed, they may be re-installed. However, this requires considerable effort and cost, and the repair itself may be difficult depending on the installation location.

  As shown in FIG. 2, typically, there are eight possible combinations of case 1 to case 8 as combinations of mounting directions and installation positions of current transformers 21 and 22. “Positive” shown in the column “Mounting direction” in FIG. 2 indicates that the mounting direction of the current transformers 21 and 22 is correct with respect to the direction of the current flowing through the R-phase wire 96R and the T-phase wire 96T. “Reverse” indicates that the mounting direction is reverse. Further, as is apparent from the column “Installation Position” in FIG. 2, in cases 1 to 4, the current transformer 21 is connected to the R-phase ports 15 Ra and 15 Rb of the power detector 15, and the current transformer 22 is the power detector. Are connected to the 15 T-phase ports 15Ta and 15Tb (that is, correctly connected), and in the case 5 to the case 8, the current transformer 21 is connected to the T-phase ports 15Ta and 15Tb of the power detection unit 15 and the current transformer 22 Are connected to the R-phase ports 15Ra and 15Rb of the power detection unit 15 (that is, they are erroneously connected). In rare cases, one or both current transformers 21 and 22 may be installed on the N-phase line 96N, or two current transformers 21 and 22 may be installed on the same-phase lines 96R and 96T. In the power generation device 1, it is possible to grasp whether the current transformers 21 and 22 are attached at appropriate positions in the correct direction and whether or not a failure has occurred in the power measurement device by the power measurement method described below. it can.

  Next, a power measurement method according to an embodiment of the present invention will be described with reference to FIGS. FIG. 3 is a flowchart illustrating the power measurement method according to the embodiment of the present invention. In addition, although the electric power measurement method which concerns on embodiment of this invention is typically performed with the electric power generating apparatus 1, you may perform with another apparatus. Before the power generator 1 is operated for the first time, an inspection is made as to whether or not the mounting directions and installation positions of the current transformers 21 and 22 are correct (S101). The inspection is performed as follows.

  Here, with reference to FIG.4 and FIG.5, it demonstrates in full detail about the process of test | inspecting the attachment direction and installation position of the current transformers 21 and 22. FIG. First, the first stage inspection process will be described with reference to FIG. In the first stage inspection process, first, the switch 25 is turned on (S1). Then, the current according to the load of the heater 12E flowing from the R-phase line 96R to the N-phase line 96N via the heater 12Er apparently increases. Here, the power detection unit 15 determines whether the input current has increased or decreased in both the R-phase ports 15Ra and 15Rb and the T-phase ports 15Ta and 15Tb (S10). If both increase or decrease, the two current transformers 21 and 22 are installed on the R-phase line 96R, or the two current transformers 21 and 22 are installed on the N-phase line 96N, or the current transformer 21 and 22 are installed one by one for the R-phase line 96R and the N-phase line 96N, and cannot be dealt with by the correction described later. Therefore, it is determined that reconnection is necessary (S91: Event NG ”). On the other hand, when it cannot be said that both have increased or decreased (in the case where there is no increase / decrease in the input current of either one of the R phase ports 15Ra, 15Rb or T phase ports 15Ta, 15Tb, or both) The process proceeds to the next step.

  When it can be said that both the R-phase ports 15Ra and 15Rb and the T-phase ports 15Ta and 15Tb have both increased or decreased in the step (S10) of determining whether the input current has increased or decreased, the power detection unit 15 determines whether or not the input current of the R-phase ports 15Ra and 15Rb has increased (S11). When it is confirmed that the input current of the R-phase ports 15Ra and 15Rb has increased, the switch 25 is turned off (S12), and then it is determined whether or not the input current of the R-phase ports 15Ra and 15Rb has decreased (S13). ). When it is confirmed that the input current of the R-phase ports 15Ra and 15Rb has decreased, it is determined that both the mounting direction and the installation position of the current transformer 21 are correct (S14: this determination is referred to as “event A”). In the step of determining whether or not the input current of the R-phase ports 15Ra and 15Rb has decreased (S13), if the decrease cannot be confirmed, it is determined that there is an abnormality in the measuring instrument (S15: this determination is referred to as “event N1 ”).

  In the step of determining whether or not the input current of the R-phase ports 15Ra and 15Rb has increased (S11), if it cannot be confirmed that the input current of the R-phase ports 15Ra and 15Rb has increased, the switch 25 is turned on. Whether or not the input current of the R-phase ports 15Ra and 15Rb has decreased is determined (S21). When it is confirmed that the input current of the R-phase ports 15Ra and 15Rb has decreased, the switch 25 is turned off (S22), and then it is determined whether or not the input current of the R-phase ports 15Ra and 15Rb has increased (S23). ). When it is confirmed that the input currents of the R-phase ports 15Ra and 15Rb have increased, it is determined that the installation position of the current transformer 21 is correct but the installation direction is reversed (S24: this determination is “event B”). ). In the step of determining whether or not the input current of the R-phase ports 15Ra and 15Rb has increased (S23), if the increase cannot be confirmed, it is determined that there is an abnormality in the measuring instrument (S25: this determination is referred to as “event N2 ”).

  In the step of determining whether or not the input current of the R-phase ports 15Ra and 15Rb has decreased (S21), if it cannot be confirmed that the input current of the R-phase ports 15Ra and 15Rb has decreased, the switch 25 is turned on. Whether or not the input current of the T-phase ports 15Ta and 15Tb has increased is determined (S31). When it is confirmed that the input current of the T-phase ports 15Ta and 15Tb has increased, the switch 25 is turned off (S32), and then it is determined whether or not the input current of the T-phase ports 15Ta and 15Tb has decreased (S33). ). When it is confirmed that the input currents of the T-phase ports 15Ta and 15Tb have decreased, it is determined that both the mounting direction and the installation position of the current transformer 21 are opposite (S34: this determination is referred to as “event C”). In the step of determining whether or not the input current of the T-phase ports 15Ta and 15Tb has decreased (S33), if the decrease cannot be confirmed, it is determined that there is an abnormality in the measuring instrument (S35: This determination is referred to as “event N3 ”).

  In the step of determining whether or not the input current of the T-phase ports 15Ta and 15Tb has increased (S31), if it cannot be confirmed that the input current of the T-phase ports 15Ta and 15Tb has increased, the switch 25 is turned on. Whether or not the input current of the T-phase ports 15Ta and 15Tb has decreased is determined (S41). When it is confirmed that the input current of the T-phase ports 15Ta and 15Tb has decreased, the switch 25 is turned off (S42), and then it is determined whether or not the input current of the T-phase ports 15Ta and 15Tb has increased (S43). ). When it is confirmed that the input currents of the T-phase ports 15Ta and 15Tb have increased, it is determined that the mounting direction of the current transformer 21 is correct but the installation position is incorrect (S44: this determination is “event D”). ). In the step of determining whether or not the input current of the T-phase ports 15Ta and 15Tb has increased (S43), it is determined whether or not the input current of the T-phase ports 15Ta and 15Tb has decreased. When the decrease cannot be confirmed in the step (S41), it is determined that there is an abnormality in the measuring device (S45: this determination is referred to as “event N4”).

  Next, the inspection process in the second stage will be described with reference to FIG. In the second stage inspection process, the result of the first stage inspection process is temporarily stored in the power detector 15, and then the switch 26 is turned on (S49). Then, the current corresponding to the load of the heater 12Et flowing from the N-phase line 96N to the T-phase line 96T via the heater 12Et is apparently increased. Here, the power detection unit 15 determines whether the input current has increased or decreased in both the R-phase ports 15Ra and 15Rb and the T-phase ports 15Ta and 15Tb (S50). If both increase or decrease, the two current transformers 21 and 22 are installed on the T-phase line 96T, or the two current transformers 21 and 22 are installed on the N-phase line 96N, or the current transformer 21 and 22 are installed one by one for the T-phase line 96T and the N-phase line 96N, and cannot be dealt with by the correction described later. Therefore, it is determined that reconnection is necessary (S92: Event NG ”). On the other hand, when it cannot be said that both have increased or decreased (in the case where there is no increase / decrease in the input current of either one of the R phase ports 15Ra, 15Rb or T phase ports 15Ta, 15Tb, or both) The process proceeds to the next step.

  When it can be said that both the R-phase ports 15Ra and 15Rb and the T-phase ports 15Ta and 15Tb have both increased or decreased in the step (S10) of determining whether the input current has increased or decreased, the power detection unit 15 determines whether or not the input current of the T-phase ports 15Ta and 15Tb has increased (S51). When it is confirmed that the input current of the T-phase ports 15Ta and 15Tb has increased, the switch 26 is turned off (S52), and then it is determined whether or not the input current of the T-phase ports 15Ta and 15Tb has decreased (S53). ). When it is confirmed that the input currents of the T-phase ports 15Ta and 15Tb have decreased, it is determined that both the mounting direction and the installation position of the current transformer 22 are correct (S54: this determination is referred to as “event E”). In the step of determining whether or not the input current of the T-phase ports 15Ta and 15Tb has decreased (S53), if the decrease cannot be confirmed, it is determined that there is an abnormality in the measuring instrument (S55: this determination is referred to as “event N5 ”).

  In the step of determining whether or not the input current of the T-phase ports 15Ta and 15Tb has increased (S51), if it cannot be confirmed that the input current of the T-phase ports 15Ta and 15Tb has increased, the switch 26 is turned on. Whether or not the input current of the T-phase ports 15Ta and 15Tb has decreased is determined (S61). When it is confirmed that the input current of the T-phase ports 15Ta and 15Tb has decreased, the switch 26 is turned off (S62), and then it is determined whether or not the input current of the T-phase ports 15Ta and 15Tb has increased (S63). ). When it is confirmed that the input currents of the T-phase ports 15Ta and 15Tb have increased, it is determined that the installation position of the current transformer 22 is correct but the installation direction is reversed (S64: this determination is “event F”). ). In the step of determining whether or not the input current of the T-phase ports 15Ta and 15Tb has increased (S63), if the increase cannot be confirmed, it is determined that there is an abnormality in the measuring instrument (S65: this determination is referred to as “event N6 ”).

  In the step of determining whether or not the input current of the T-phase ports 15Ta and 15Tb has decreased (S61), if it cannot be confirmed that the input current of the T-phase ports 15Ta and 15Tb has decreased, the switch 26 is turned on. Whether the input current of the R-phase ports 15Ra and 15Rb has increased or not is determined (S71). When it is confirmed that the input current of the R-phase ports 15Ra and 15Rb has increased, the switch 26 is turned off (S72), and then it is determined whether or not the input current of the R-phase ports 15Ra and 15Rb has decreased (S73). ). When it is confirmed that the input currents of the R-phase ports 15Ra and 15Rb have decreased, it is determined that both the mounting direction and the installation position of the current transformer 22 are opposite (S74: this determination is referred to as “event G”). In the step of determining whether or not the input current of the R-phase ports 15Ra and 15Rb has decreased (S73), if the decrease cannot be confirmed, it is determined that there is an abnormality in the measuring instrument (S75: this determination is referred to as “event N7 ”).

  In the step of determining whether or not the input current of the R-phase ports 15Ra and 15Rb has increased (S71), if it cannot be confirmed that the input current of the R-phase ports 15Ra and 15Rb has increased, the switch 26 is turned on. Whether or not the input current of the R-phase ports 15Ra and 15Rb has decreased is determined (S81). When it is confirmed that the input current of the R-phase ports 15Ra and 15Rb has decreased, the switch 26 is turned off (S82), and it is then determined whether or not the input current of the R-phase ports 15Ra and 15Rb has increased (S83). ). When it is confirmed that the input currents of the R-phase ports 15Ra and 15Rb have increased, it is determined that the mounting direction of the current transformer 22 is correct but the installation position is incorrect (S84: this determination is “event H”). ). In the step of determining whether or not the input current of the R-phase ports 15Ra and 15Rb has increased (S83), it is determined whether or not the increase has been confirmed and whether or not the input current of the R-phase ports 15Ra and 15Rb has decreased. When the decrease cannot be confirmed in the step (S81), it is determined that there is an abnormality in the measuring device (S85: this determination is referred to as “event N8”).

  By the above-described inspection process, it is grasped in which case the installation state of the current transformers 21 and 22 corresponds to which case shown in FIG. 2 or is installed at a position that cannot be dealt with by correction by the power detection unit 15 described later. Is done. Case 1 corresponds to event A and event E. Case 2 corresponds to event B and event E. When it is determined that the event A and the event F, it corresponds to the case 3. If it is determined that the event B and the event F, it corresponds to Case 4. Case 5 corresponds to event C and event G. If it is determined that the event D and the event G, it corresponds to Case 6. Case 7 corresponds to event C and event H. Case 8 corresponds to event D and event H. If the installation state of current transformers 21 and 22 is grasped by this inspection process, it will progress to the process (S102 in Drawing 3) of judging whether the attachment direction and installation position of current transformers 21 and 22 are right. In the above description of the inspection process in the first stage and the second stage, the case where the inspection is started from a state where the heaters 12Er and 12Et are not energized is shown. When the inspection is started from the state where the heaters 12Er and 12Et are energized, the switches 25 and 26 may be switched on and off and the port currents may be increased and decreased in the flowcharts of FIGS.

  Returning to FIG. 3 again, the description of the power measurement method will be continued. Based on the result of the above-described inspection step (S101), it is determined whether the mounting direction and the installation position of the current transformers 21 and 22 are correct (S102). If it is determined in the inspection step (S101) that the case 1 shown in FIG. 2 is satisfied, the result is correct. If it is correct, the process proceeds to the step of calculating power (S105), and if not correct, the measurement device (the power detection unit 15 or the current transformer) 21 or 22), or whether or not the installation positions of the current transformers 21 and 22 are installed at positions that cannot be accommodated by correction by the power detection unit 15 described later (S103). ) In the step (S103) for judging abnormality of the measuring device, etc., if any of the cases 2 to 8 shown in FIG. It progresses to the process (S104) which correct | amends the electric current value detected with the flow devices 21 and 22. FIG. The case where it is determined that there is an abnormality in the step (S103) of determining abnormality of the measuring device will be described later.

  In the step of correcting the current value (S104), the power detection unit 15 performs correction based on the result of the above-described inspection step (S101). When the attachment direction shown in FIG. 2 is determined to be “reverse”, the detected current value is switched between positive and negative. If it is determined that the input position is incorrect, the value input to the R-phase port is regarded as the power value detected by the current transformer 22, and the current input to the T-phase port is detected by the current transformer 21. Considered power value. In this way, the value input to the power detection unit 15 is corrected. When the current value is corrected, the process proceeds to a step of calculating power (S105).

  In the step of calculating power (S105), the calculation is performed by applying the detected current value and voltage value to the formula for obtaining the power value from the above-described current value and voltage value stored in advance in the power detection unit 15. Do. The calculated power value is reflected in the control of the output of the fuel cell 11. After calculating the power, it is determined whether or not a predetermined time has elapsed since the previous inspection (S101) (S106). If the predetermined time has not elapsed, the process returns to the power calculation step (S105) to recalculate the power value and reflect it in the control of the output of the fuel cell 11. If the predetermined time has elapsed, the process returns to the inspection step (S101) and the inspection is performed again. When returning to the inspection process, the count for a predetermined time (S106) is reset.

  Now, in the step (S103) of determining abnormality of the measuring device, it is determined that the installation positions of the current transformers 21 and 22 are installed at positions that cannot be handled by the correction by the power detection unit 15. 4 and FIG. 5, the case corresponds to the event NG. In this case, since it cannot cope with the above-described correction, the operation of the power generator 1 is stopped and an alarm is issued (S109). 4 and 5, the step (S10, S50) of determining whether or not the input currents of the R-phase ports 15Ra and 15Rb and the T-phase ports 15Ta and 15Tb are both increased or decreased is the first stage. One or both of the current transformers 21 and 22 are implemented by performing twice after the switch 25 in the inspection process is turned on (S1) and after the switch 26 in the second stage inspection process is turned on (S49). Is surely grasped whether or not is installed on the N-phase line 96N. For example, when the current transformer 21 is attached to the N-phase line 96N with the mounting direction reversed, and the current transformer 22 is attached to the T-phase line 96T and the mounting direction is positive to the T-phase line 96T, the switch 25 is turned on. When (S1) is turned off (S12), the current is detected as if the current transformer 21 is attached to the R-phase line 96R with the mounting direction being positive, but the switch 26 is turned on (S49) and turned off (S49). When S52), it is detected that the current transformer 21 is attached to the N-phase line 96N in the reverse direction. In addition, two current transformers can be obtained by performing twice (S10, S50) the process of determining whether or not both of the input currents of the R-phase ports 15Ra and 15Rb and the T-phase ports 15Ta and 15Tb have increased or decreased. It can be ascertained that 21 and 22 are arranged on the same phase line (96R, 96N, 96T).

  On the other hand, in the step (S103) of determining the abnormality of the measuring device, it is determined that there is an abnormality of the measuring device in any of the events N1 to N8 in FIGS. No case 1 to case 8 shown in FIG. In this case, since the detection of the current when the currents of the R-phase line 96R and the T-phase line 96T are changed does not conform to the actual change, there is a high possibility that an abnormality has occurred in the measuring instrument. From the viewpoint of safety, when it is determined that there is an abnormality in the step of determining an abnormality of the measuring device (S103), the operation of the power generator 1 is stopped and an alarm is issued (S109). In this way, by performing the inspection step (S101) periodically even during operation of the power generation device 1, it is possible to detect an abnormality in the power generation device 1 without delay. In the second and subsequent inspection steps (S101), it is usually not considered that the mounting direction and the installation position of the current transformers 21 and 22 have changed compared to the first inspection. The main purpose is to discover abnormalities.

  In the above description, the fuel cell 11 has been described as a solid polymer fuel cell, but it may be a fuel cell other than a solid polymer fuel cell such as a phosphoric acid fuel cell.

  In the above description, the power generation unit is a fuel cell, but may be a generator. In addition, when the power generation unit is an AC generator, the inverter 13 may be omitted.

  In the above description, the commercial power supply 98 connected to the power generation system 10 has been described as being a single-phase AC, but may be a three-phase AC. When the commercial power source is a three-phase alternating current, even if there are two current transformers, the circuit shown in FIG. 1 can be used by using the so-called two-watt meter method based on the Blondel theorem.

  In the above description, the switches 25 and 26 are described as being disposed immediately upstream of the heater 12E. However, the switches 25 and 26 may be disposed at a position for controlling the supply of electric power to the other auxiliary machines 12. However, when performing the inspection, it is preferable to arrange the switches 25 and 26 immediately upstream of the heater 12E, in which a change in electric power is easy to confirm and the verification operation hardly affects the power generation system 10.

It is a distribution diagram explaining a power generator concerning an embodiment of the invention. It is a figure which shows the combination pattern of the attachment direction and installation position of a current transformer. It is a flowchart explaining the electric power measurement method which concerns on embodiment of this invention. It is a flowchart explaining the inspection process of the 1st step of an electric power measurement method. It is a flowchart explaining the inspection process of the 2nd step of an electric power measurement method.

Explanation of symbols

11 Fuel cell (power generation part)
12 Auxiliary machinery (electric power load)
15 Power detection unit (control device)
15Ra, 15Rb First current input terminal 15Ta, 15Tb Second current input terminal 15Vr, 15Vt, 15Vn Voltage input terminal 21 Current transformer (first current detector)
22 Current transformer (second current detector)
23 Transformer (voltage detector)
25 1st switch 26 2nd switch 96R R phase line (1st cable)
96T T-phase wire (second cable)
99 Electricity load

Claims (7)

A power measurement method for measuring AC power using a current transformer;
Inspecting the installation status of the current transformer;
Correcting the current value detected by the current transformer based on the inspection result;
Calculating power based on the corrected current value;
Power measurement method. The step of inspecting includes a step of changing a magnitude of a current detected by the current transformer, and a step of confirming whether or not there is a change in a detected value of the current transformer in accordance with a change in the magnitude of the current. Composed of;
The power measurement method according to claim 1. The power to be measured is power supplied from a commercial power source linked to power generated by the fuel cell;
The power measuring method according to claim 1 or 2. A first current detector for detecting a current flowing through a first cable connected to a power load supplied with AC power;
A second current detector for detecting a current flowing through a second cable connected to the power load;
A voltage detector for detecting the voltage of the first cable and the voltage of the second cable;
A power generation unit that generates power to be supplied to the power load;
A first current input terminal for inputting a current value detected by the first current detector, a second current input terminal for inputting a current value detected by the second current detector, and a detection by the voltage detector A voltage input terminal for inputting a voltage value, based on a current value detected by the first current detector, a current value detected by the second current detector, and a voltage value detected by the voltage detector; Provided with a control device for calculating the power value;
The controller changes the magnitude of the current flowing through the first cable to inspect the magnitude and change of the current values of the first current detector and the second current detector; and By changing the magnitude of the current flowing through the second cable, the magnitude of the current value of the first current detector and the second current detector and the presence or absence of the change are inspected. It is configured to determine whether the installation direction and the installation position of the detector and the second current detector are appropriate, and to calculate the power value by correcting the detected current value when it is not appropriate;
Power generation device. The current detector comprises a clamp-type current transformer;
The power generation device according to claim 4. One of the power loads is composed of an auxiliary machine related to the operation of the power generation unit;
The first cable has a first switch for supplying and cutting off current to the auxiliary machine, and the second cable has a second switch for supplying and cutting off electric current to the auxiliary machine;
The magnitude of the current flowing through the first cable is changed by switching the first switch, and the magnitude of the current flowing through the second cable is changed by switching the second switch. Was;
The power generation device according to claim 4 or 5. The power generation unit comprises a fuel cell;
The power generator according to any one of claims 4 to 6.

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