JP2014073035A - Power generating system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a power generating system capable of preventing breakage of a current sensor because no high voltage occurs on the secondary side even when an electric current runs through the primary side of a current transformer under a non-input state of a detection signal of the current sensor.SOLUTION: A power generating system includes a current sensor switching device 108 that executes switching to input, into a power generator 103, a detection signal of a first current sensor 104 for detecting an electric current running through an electrical wire between a commercial power supply 101 and the power generator 103 under a normal state of the commercial power supply 101 and to input, into the power generator 103, a detection signal of a second current sensor 105 for detecting an electric current running through an electrical wire between an AC power supply 102 and the power generator 103 under a power failure state, and further includes a load resistance connected between each of the current sensors and a current sensor switching device 108.

Description

  The present invention relates to a power generation system in which two or more distributed power generators are provided and connected to a commercial power source.

  Conventionally, this type of power generation system has a configuration shown in FIG. 4, for example (see, for example, Patent Document 1).

  Below, the electric power generation system shown by patent document 1 is demonstrated.

  FIG. 4 is a block diagram of a conventional power generation system.

  As shown in FIG. 4, the power generation system includes a power generation unit 2, an AC power supply device 10, a first sensor 12, and a second sensor 21.

  The power generation unit 2 includes a generator 4 driven by a gas engine, an inverter 5 that converts the power generation output of the power generator 4 into AC power, and an output control unit 7 that performs operation and output control of the power generation unit 2. Is done.

  The AC power supply 10 includes a single-phase three-wire sine wave output uninterruptible power supply 11 and a first sensor for detecting the output power of the uninterruptible power supply 11 provided on the output line of the uninterruptible power supply 11. 12, three switches SW1 to SW3, one power input terminal Ip, three power output terminals Op1 to Op3, one signal input terminal Is, and one output terminal Os. ing.

  The first sensor 12 is configured by providing one current transformer for each of two voltage lines of the output line (single-phase three-wire type) of the uninterruptible power supply 11. Therefore, the first sensor 12 detects the output current value of the uninterruptible power supply 11, that is, the total current consumption of the load on the downstream side of the uninterruptible power supply 11.

  The second sensor 21 is provided on an input line that inputs to the first distribution board 22 of the commercial AC power source PS, and is connected to two voltage lines of the input line (single-phase three-wire type) of the commercial AC power source PS. On the other hand, each current transformer is provided. Therefore, the second sensor 21 detects the input current value of the commercial AC power supply PS, that is, the total current consumption of the load on the downstream side of the second sensor 21.

  The detection output of the second sensor 21 is connected to the signal input terminal Is of the AC power supply device 10. Further, the signal output terminal Os of the AC power supply apparatus 10 and the output control unit 7 of the power generation unit 2 are connected, and the detection signal of either the first sensor 12 or the second sensor 21 is selected by the switch SW3, and the signal output terminal The signal is input to the output control unit 7 via Os.

  In the power generation system configured as described above, when the commercial AC power supply PS is normal, the detection signal of the second sensor 21 is input to the output control unit 7, and the output control unit 7 simultaneously applies the voltage applied to the output line of the power generation unit 2. That is, the power generation unit measures the voltage value of the commercial AC power source PS, calculates the power from the current value of the commercial AC power source PS obtained from the detection signal of the second sensor 21, and prevents a reverse power flow to the commercial AC power source PS side. 2 output control is performed.

  When the commercial AC power supply PS is in a power failure, the detection signal of the first sensor 12 is input to the output control unit 7, and the output control unit 7 simultaneously determines the voltage applied to the output line of the power generation unit 2, that is, the voltage value of the uninterruptible power supply 11. The power is calculated from the current value of the uninterruptible power supply 11 obtained from the detection signal of the first sensor 12, and the output control of the power generation unit 2 is performed so as not to flow backward to the uninterruptible power supply 11 side.

JP 2004-242458 A

  However, in the conventional configuration, in the state of the commercial AC power supply PS, the detection signal of either the first sensor 12 or the second sensor 21 is input to the output control unit 7 of the power generation unit 2 and at the same time The detection signal of this sensor is in a non-input state. In other words, in the non-input state current sensor, the secondary side of the current transformer is opened, so when the primary current flows, a high voltage is generated on the secondary side in an attempt to flow the secondary current, and the current sensor is damaged. It had the problem of end.

  The present invention solves the above-described conventional problems, and is configured to connect a load resistor so that the secondary side of the current transformer is not opened even when the detection signal of the current sensor is not input. An object of the present invention is to provide a power generation system capable of preventing damage to a current sensor because no high voltage is generated on the secondary side even when current flows on the primary side.

  In order to solve the above-described conventional problems, the power generation system of the present invention is connected to an AC power supply device capable of AC output and a commercial power supply when the commercial power supply is normal, and at a power failure of the commercial power supply A power generation device that outputs AC power in linkage with an AC power supply device, a first current sensor that detects a current flowing in an electric wire between the commercial power supply and the power generation device, the AC power supply device, and the power generation device A second current sensor that detects a current flowing through the electric wire between the first power sensor and the detection signal of the first current sensor when the commercial power source is normal, and the power source when the commercial power source is out of power A current sensor switching unit that performs switching so that a detection signal of the second current sensor is input to the power generation device, and is negative between each of the first current sensor and the second current sensor and the current sensor switching unit; It is an arrangement for connecting the resistors.

  As a result, the load resistance is connected so that the secondary side of the current transformer is not opened even when the detection signal of the current sensor is not input, so that even if a current flows to the primary side of the current transformer, 2 Since no high voltage is generated on the secondary side, the current sensor can be prevented from being damaged.

  The power generation system of the present invention has a configuration in which a load resistor is connected so that the secondary side of the current transformer is not opened even when the detection signal of the current sensor is not input, so that a current is supplied to the primary side of the current transformer. Even if it flows, a high voltage is not generated on the secondary side, so that the current sensor can be prevented from being damaged.

Block diagram of the power generation system in Embodiment 1 of the present invention Detailed view and peripheral view of current and power detection in the same embodiment Block diagram of a power generation system according to Embodiment 2 of the present invention Block diagram of a conventional power generation system

  According to a first aspect of the present invention, an AC power supply capable of AC output is linked to a commercial power supply when the commercial power supply is normal, and is linked to the AC power supply device during a power failure of the commercial power supply. , A first current sensor that detects a current flowing through the electric wire between the commercial power supply and the power generating device, and a current flowing through the electric wire between the AC power supply device and the power generating device. The detection signal of the first current sensor is input to the power generation device when the second current sensor and the commercial power supply are normal, and the detection signal of the second current sensor is input to the power generation device during a power failure of the commercial power supply. A current sensor switching unit that performs switching so as to input to the load sensor, and a load resistor is connected between each of the first current sensor and the second current sensor and the current sensor switching unit. As a result, the load resistor is connected so that the secondary side of the current transformer is not opened even when the detection signal of the current sensor is not input, so that even if a current flows to the primary side of the current transformer, 2 Since no high voltage is generated on the secondary side, the current sensor can be prevented from being damaged.

  According to a second aspect of the invention, in particular, in the first aspect of the invention, the power generation system further includes a switch for connecting or disconnecting the load resistance, and the switch is connected by the switch according to the switching of the current sensor switch. Control whether to disconnect. This eliminates the need to consider load resistance when calculating power based on information from the current sensor, making it easy to cope with changes in load resistance due to changes in the current sensor and changes in power calculation in the power generator. can do.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In addition, this invention is not limited by this embodiment.

(Embodiment 1)
Hereinafter, the power generation system according to Embodiment 1 of the present invention will be described in detail.

  FIG. 1 is a block diagram of a power generation system according to Embodiment 1 of the present invention. FIG. 2 is a detailed view and a peripheral view of current and power detection in the same embodiment.

  In FIG. 1, a commercial power supply 101, an AC power supply device 102, a power generation device 103, a first distribution board 109, a second distribution board 112, a first current sensor 104, a second current sensor 105, A commercial power connector 106, a power switch 107, and a current sensor switch 108 are illustrated.

  Here, the commercial power source 101 is a single-phase three-wire AC power source.

  The first distribution board 109 is connected to the power generator 103 via the commercial power source 101, the commercial power connector 106, and the power switch 107. In addition, a load 110 such as a television set or an air conditioner used in a general household that consumes power supplied from the commercial power supply 101 and the power generation apparatus 103 is connected. Here, the commercial power supply connector 106 connects / disconnects the commercial power supply 101 and the power supply line of the power generation apparatus 103 according to the state of the commercial power supply 101. The power switch 107 switches the power generation device 103 to either the commercial power source 101 or the AC power source device 102 according to the state of the commercial power source 101.

  The second distribution board 112 is connected to the commercial power supply 101 or the AC power supply apparatus 102 and the power generation apparatus 103 via the power switch 107. In addition, a load 111 such as a television set or an air conditioner used in a general household that consumes power supplied from the commercial power supply 101 or the AC power supply apparatus 102 and the power generation apparatus 103 is connected.

  The first current sensor 104 is a clamp-type current sensor, and is provided on an input line through which the commercial power supply 101 is input to the first distribution board 109. The first current sensor 104 is a 2 of the input line (single-phase three-wire type) of the commercial power supply 101. One voltage transformer is provided for each voltage line. Therefore, the first current sensor 104 detects the current value of the commercial power supply 101, that is, the total current consumption of the load on the downstream side of the first current sensor 104.

  The second current sensor 105 is a clamp-type current sensor, and is configured by providing one current transformer for each of the two voltage lines of the output line (single-phase three-wire type) of the AC power supply apparatus 102. Therefore, the second current sensor 105 detects the current value of the AC power supply device 102, that is, the total current consumption of the load on the downstream side of the AC power supply device 102.

  The current sensor switching unit 108 inputs the detection signal of the first current sensor 104 to the output controller 116 of the power generator 103 when the commercial power source 101 is normal and the detection signal of the second current sensor 105 when the commercial power source 101 is out of power. It is to switch as follows.

  The power generation apparatus 103 includes at least a power generator 114, a power converter 115, and an output controller 116.

Here, the generator 114 is composed of a fuel cell or the like and generates DC power.
The power converter 115 has a configuration including an insulating transformer, transforms the DC voltage generated by the power generator 114, and converts it into AC that can be consumed by the loads 110 and 111.

  The output controller 116 calculates power from the current value from the first current sensor 104 or the second current sensor 105 connected via the current sensor switching unit 108 and the voltage value from the voltage sensor (not shown). The output of the power generator 114 and the power converter 115 is controlled. The output controller 116 only needs to have an arithmetic processing function. Examples of the output controller 116 include a microcontroller, CPU, MPU, logic circuit, PLC (Programmable Logic Controller), and the like.

  2 includes a first current sensor 104, a second current sensor 105, a current sensor switch 108, an output controller 116 of the power generation apparatus 103, and a load resistor 117.

  Here, in the first current sensor 104 and the second current sensor 105, the load resistor 117 is connected to both ends of the detection signal on the current transformer side from the current sensor switch 108.

  The operation and action of the power generation system configured as described above will be described with reference to FIGS.

  First, the power calculation by the output controller 116 of the power generation apparatus 103 will be specifically described with reference to FIG.

  The output control unit 116 of the power generation apparatus 103 detects the voltage value by dividing the AC voltage generated by the commercial power supply 101 or the AC power supply apparatus 102 with the voltage sensor 116c, and also detects the voltage value, and the second current sensor 104 or the second current sensor 104. Based on a detection signal from the current sensor 105, a voltage determined by a combined current of the secondary current generated on the secondary side of the current transformer and the load resistance 116a and the load resistance 117 when a current flows on each wire. Based on the current value.

Then, the voltage value to be detected and the current value are integrated by a multiplier 116d to obtain a positive AC signal of zero or more, and then a DC signal is obtained by a filter circuit 116e. This DC signal is amplified by the signal amplification circuit 116f, and is converted into an insulation-amplified DC signal that can be input to the A / D input port of the control unit 116i by the digital isolation amplifier 116g. Further, the signal is amplified by the signal amplification circuit 116h and input to the A / D input port of the control unit 116i. With these configurations, the output controller 116 calculates power.

  Next, the operation of the power generation system will be described with reference to FIGS.

  When the commercial power supply 101 is normal, the AC power supply apparatus 102 turns on the commercial power supply connector 106 and connects the commercial power supply 101 and the power generation apparatus 103 by the power switch 107. In addition, the detection signal of the first current sensor 104 is input to the power generator 103 so that the output controller 116 of the power generator 103 can measure the input power of the first distribution board 109 by the current sensor switch 108. Thus, the detection signal of the second current sensor 105 is set to the non-input state.

  The output controller 116 of the power generation apparatus 103 calculates the power demand based on the current value of the first current sensor 104, and plans the operation of the power generation apparatus 103 in a predetermined unit time. The predetermined unit time may be a long period such as a unit from one day to a week. As an example, the data of power demand in the user's home is collected on a daily basis, and the operation start time and end time are calculated so that the operation is performed in a time zone where the demand is greatest. And based on an operation plan, it starts by the electric power supply from the commercial power supply 101, and after power generation, while changing output electric power according to an electric power demand, output control is performed so that a reverse power flow may not be carried out to the commercial power supply 101. FIG.

  At this time, the detection signal of the second current sensor 105 is not input to the output controller 116 of the power generation apparatus 103 and is in a non-input state. In such a state, for example, when the second power sensor is clamped on the power generation device 103 side in the power switch 107 that can detect the output power of the AC power supply device 102 by mistake, the first change depending on the operation state of the load 111. A primary current flows on the electric wire clamped by the two-current sensor 105, and a secondary current is generated on the secondary side of the current transformer. However, since the load resistor 117 is connected to both ends of the detection signal, no high voltage is generated on the secondary side of the current transformer.

  Next, the commercial power supply 101 will be described when a power failure occurs.

  When the AC power supply 102 detects a power failure of the commercial power supply 101, the commercial power supply connector 107 is turned off to disconnect the commercial power supply 101 and the power generation apparatus 103 and connect the AC power supply apparatus 102 and the power generation apparatus 103 by the power supply switch 107. To do. In addition, the detection signal of the second current sensor 105 is input to the power generation apparatus 103 so that the output controller 116 of the power generation apparatus 103 can measure the output power of the AC power supply apparatus 102 by the current sensor switch 108. The detection signal of the first current sensor 104 is set to a non-input state. Then, the output controller 116 of the power generation apparatus 103 is activated by power supply from the AC power supply apparatus 102, and performs output control so as not to flow backward to the AC power supply apparatus 102 after power generation.

  At this time, the detection signal of the first current sensor 104 is not input to the output controller 116 of the power generation apparatus 103 and is in a non-input state. In such a state, for example, when the commercial power supply 101 becomes normal and power supply is started to the load 110 of the first distribution board 109, the first current sensor 104 is clamped depending on the operating state of the load 111. In FIG. 1, a primary current flows and a secondary current is generated on the secondary side of the current transformer. However, since the load resistor 117 is connected to both ends of the detection signal, no high voltage is generated on the secondary side of the current transformer.

  In this embodiment, two AC power sources, ie, the commercial power source 101 and the AC power source device 102 are used. However, an AC power source device may be used instead of the commercial power source 101.

  In the present embodiment, two AC power supplies and two current sensors for measuring the respective input / output powers are used. However, three or more AC power supplies and the three input / output powers are measured. A configuration using two current sensors may be used.

  In the present embodiment, in the current sensor switching unit 108, either the first current sensor 104 or the second current sensor 105 is input to the power generation device 103. However, the power generation device 103 and the first current sensor 104, a switch is provided between the power generation device 103 and the second current sensor 105, and either the first current sensor 104 or the second current sensor 105 is input to the power generation device 103 by controlling the switch. It doesn't matter. At this time, in order not to be in the input state at the same time, a period in which both switches are turned off may be provided.

  At this time, in order to prevent simultaneous input of the first current sensor 104 and the second current sensor 105 to the power generation apparatus 103, a period in which both switches are turned off may be provided.

  In the present embodiment, the switch 118 is configured to be connected to any one of the load resistor 117, the first current sensor 104, and the second current sensor 105. However, the first current sensor, the load resistor, and the second resistor are connected. The current sensor 105 and each of the load resistors may be connected.

  As described above, in the present embodiment, the load resistor is connected so that the secondary side of the current transformer is not opened even when the detection signals of the first current sensor 104 and the second current sensor 105 are not input. By doing so, even if a current flows through the primary side of the current transformer, no high voltage is generated on the secondary side, so that the current sensor can be prevented from being damaged.

(Embodiment 2)
Hereinafter, the power generation system according to Embodiment 2 of the present invention will be described in detail.

  FIG. 3 is a detailed view and a peripheral view of current and power detection in the present embodiment.

  Here, FIG. 3 differs from FIG. 2 in that either the first current sensor 104 or the second current sensor 105 includes a switch that connects a load resistor 117 at both ends of the detection signal. In FIG. 3, the same components as those in FIG.

  Below, operation | movement and an effect | action of the electric power generation system of this Embodiment are demonstrated using FIG. Here, since the operations of the AC power supply device 102, the power generation device 103, the commercial power supply connector 106, the power supply switch 107, and the current sensor switch 108 are the same as those in the first embodiment, the description thereof is omitted.

  When the commercial power supply 101 is normal, the AC power supply apparatus 102 causes the switch 118 to connect the load resistor 117 to both ends of the detection signal of the second current sensor 105.

  In the non-input state where the detection signal of the second current sensor 105 is not input to the output controller 116 of the power generation device 103, for example, in the power supply switch 107 that can detect the output power of the AC power supply device 102 by mistake. When the second current sensor is clamped on the power generation device 103 side, the primary current flows on the electric wire clamped by the second current sensor 105 depending on the operation state of the load 111, and the secondary current is generated on the secondary side of the current transformer. Occur. However, since the load resistor 117 is connected to both ends of the detection signal, no high voltage is generated on the secondary side of the current transformer.

  On the other hand, since the detection signal of the first current sensor 104 is not connected to the load resistor 117 by the switch 118, the output controller 116 of the power generator 103 is generated on the secondary side of the current transformer when the current flows on the electric wire. The current value is detected based on the voltage determined by the secondary current and the load resistance 116a. That is, it is not necessary to consider the resistance value of the load resistor 117 in the power calculation.

  Next, the operation when the commercial power supply 101 is out of power will be described.

  When the AC power supply apparatus 102 detects a power failure of the commercial power supply 101, the load resistor 117 is connected to both ends of the detection signal of the first current sensor 104 by the switch 118.

  In the non-input state, the detection signal of the first current sensor 104 is not input to the output controller 116 of the power generation apparatus 103, for example, the commercial power supply 101 becomes normal, and power supply to the load 110 of the first distribution board 109 is started. In this case, the primary current flows on the electric wire clamped by the first current sensor 104 depending on the operation state of the load 111, and the secondary current is generated on the secondary side of the current transformer. However, since the load resistor 117 is connected to both ends of the detection signal, no high voltage is generated on the secondary side of the current transformer.

  On the other hand, the detection signal of the second current sensor 105 is not connected to the load resistor 117 by the switch 118, so that the output controller 116 of the power generator 103 is generated on the secondary side of the current transformer when a current flows on the electric wire. The current value is detected based on the voltage determined by the secondary current and the load resistance 116a. That is, it is not necessary to consider the resistance value of the load resistor 117 in the power calculation.

  In the present embodiment, in the switch 118, either the first current sensor 104 or the second current sensor 105 is connected to the load resistor 117. However, the first current sensor 104 and the current sensor switch 108 are used. During this time, a switch is provided between the second current sensor 105 and the current sensor switching unit 108, and either the first current sensor 104 or the second current sensor 105 is connected to the load resistor 117 by controlling the switch. It doesn't matter if you do. At this time, in order to prevent simultaneous connection of the first current sensor 104 and the second current sensor 105 to the load resistor 117, a period in which both switches are turned off may be provided.

  As described above, in the present embodiment, the output controller 116 does not need to consider the load resistance 117 when performing power calculation based on information from the first current sensor 104 and the second current sensor 105. Thus, it is possible to easily cope with a change in load resistance due to a change in the current sensor and a change in power calculation in the power generator.

  As described above, the power generation system according to the present invention is configured such that the load resistance is connected so that the secondary side of the current transformer is not opened even when the detection signal of the current sensor is not input. Even if current flows through the primary side, no high voltage is generated on the secondary side, and the current sensor can be prevented from being damaged. Therefore, the fuel cell power generator, solar power generator, wind power generator, solar thermal power generator It can also be applied to uses such as a power generation system such as a gas engine.

DESCRIPTION OF SYMBOLS 101 Commercial power supply 102 AC power supply device 103 Electric power generation device 104 1st current sensor 105 2nd current sensor 108 Current sensor switch 117 Load resistance 118 Switch

Claims (2)

An AC power supply capable of AC output;
A power generator that is connected to a commercial power supply when the commercial power supply is normal, and that is connected to the AC power supply apparatus during a power failure of the commercial power supply to output AC power;
A first current sensor for detecting a current flowing in an electric wire between the commercial power source and the power generation device;
A second current sensor for detecting a current flowing in an electric wire between the AC power supply device and the power generation device;
When the commercial power supply is normal, the detection signal of the first current sensor is input to the power generation device, and when the commercial power supply is interrupted, switching is performed so that the detection signal of the second current sensor is input to the power generation device. Equipped with a current sensor switch to perform,
A power generation system configured to connect a load resistance between each of the first current sensor and the second current sensor and the switch. The power generation system further includes:
A switch for connecting or disconnecting the load resistor;
The power generation system according to claim 1, wherein the switch is connected or disconnected by the switch according to switching of the current sensor switch.

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