JP2004088889A - Interconnected system power generator and control method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To attain manufacturing cost reduction for an inverter device and to increase a high power control speed. <P>SOLUTION: A controller 110 detects the rotational speed of a gas engine 13 or a generator 14, and sets matched power, or power matched with commercial power, generated on the basis of a detected rotational speed in converting the power obtained by power generation into the matched power. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a grid-connected power generation device that converts power generated by using a gas engine or the like as an energy source to link it with commercial power, and a control method thereof.
[0002]
[Prior art]
2. Description of the Related Art In recent years, a cogeneration system in which a generator is driven by a gas engine to use both generated heat and electric power is becoming widespread. In this cogeneration system, there is also known a system in which electric power generated by a gas engine is connected to commercial electric power and supplied to an on-premise load, thereby functioning as a grid-connected electric power generation device for efficiently using energy.
[0003]
In such a grid-connected power generation device, the generated power is converted into a frequency, a phase, and a voltage corresponding to the commercial power via the inverter device, and the power is connected to the commercial power and supplied to the premises load. .
[0004]
[Problems to be solved by the invention]
By the way, in the above-mentioned conventional cogeneration system, when superimposing and supplying commercial power via the inverter device, the inverter device is provided with a communication function, and the main controller directly controls the amount of power supplied to the inverter using communication. The control configuration was adopted.
[0005]
For this reason, an inverter having a communication function is required as an inverter, and the control speed of the inverter is slow. In order to improve the control speed, the system construction cost is increased, and it is necessary to install a dedicated control program. There was a problem that the period was prolonged.
[0006]
Accordingly, an object of the present invention is to provide a grid-connected power generation device capable of improving the control speed of an inverter in a cogeneration system and shortening the development period, and a control method thereof.
[0007]
[Means for Solving the Problems]
In order to solve the above-mentioned problems, a grid-connected power generation apparatus having an engine and a generator driven by the engine to generate electric power is operated by detecting operation information that is information on an operation state of the engine or the generator. An information detection unit, and a power amount setting unit configured to set a power amount of the matched power to be generated based on the operation information when converting the power obtained by the power generation into matched power that is power matched with commercial power. And, it is characterized by having.
[0008]
According to the configuration, the operation information detection unit detects operation information that is information on the operation state of the engine or the generator.
[0009]
The power amount setting unit sets the power amount of the matching power to be generated based on the operation information when converting the power obtained by the power generation into the matching power that is the power matching the commercial power.
[0010]
Also, in a system interconnection generator including an engine, a generator that is driven by the engine, generates electric power, and an inverter unit that converts electric power obtained by the electric power generation into matched electric power that is electric power matched to commercial electric power, The operation information detection unit of the inverter unit detects operation information that is information on the operation state of the engine or the generator.
[0011]
Accordingly, the power amount setting unit sets the power amount of the matching power to be generated based on the operation information when converting the power obtained by the power generation into the matching power that is the power matching the commercial power.
[0012]
In these cases, the operation information may be information on a rotation speed of a rotor of the engine or the generator.
[0013]
Further, the operating state of the engine may be set based on the set amount of supplied power.
[0014]
Also, a control method of a grid-connected power generation apparatus having an engine and a generator driven by the engine to generate power includes operating information detection for detecting operation information that is information on an operation state of the engine or the generator. A power amount setting step of setting a power amount of the matched power to be generated based on the operation information, when converting the power obtained by the power generation into matched power which is power matched with commercial power, It is characterized by having.
[0015]
In this case, the operation information may be information on a rotation speed of a rotor of the engine or the generator.
[0016]
An engine operating state setting step of setting an operating state of the engine based on the set amount of supplied power may be provided.
[0017]
BEST MODE FOR CARRYING OUT THE INVENTION
Next, a preferred embodiment of the present invention will be described with reference to the drawings.
[0018]
FIG. 1 is a partially cutaway perspective view of a cogeneration system mainly for power supply according to the embodiment.
[0019]
The cogeneration system 100 roughly includes a machine room 1, a heat storage room 2, and a heat release room 3.
[0020]
In the machine room 1, a bottom plate 11 is mounted on a base member 10, and the bottom plate 11 is provided with a vent 12. A gas engine (drive source) 13 as an internal combustion engine and a generator 14 driven by the driving force of the gas engine 13 are provided on the bottom plate 11. In the present embodiment, the generator 14 generates three-phase AC power.
[0021]
Further, a cooling water pump 15, an exhaust gas device 16, and a fuel supply device (not shown) are housed in the machine room 1, and the machine room 1 is covered with an exterior panel 20 and an exterior panel 21.
[0022]
As shown in FIG. 1, the heat storage chamber 2 houses a hot water tank 17 fixed at an angle on the base member 10, and the heat storage chamber 2 includes an exterior panel 25, an exterior panel 26, and a top panel 24. And covered by.
[0023]
Further, the heat radiating chamber 3 is supported by steel materials 18 a to 18 c and a steel material 19 in the upper part of the machine room 1. A drain pan 31 is provided on the bottom surface of the heat radiating chamber 3, and a partition plate 27 is attached to a side wall on the heat storage chamber 2 side. The radiator 32, a radiator 32, a control box 33, and a blower 34 are housed in the radiator chamber 3.
[0024]
Furthermore, the heat radiating chamber 3 is covered with the exterior panel 22, the exterior panel 23 provided with the slit 35, and the top panel 24 having the outlet 29 to which the exhaust top 30 and the outlet grill 28 are attached. I have.
[0025]
Here, the radiator 32 circulates cooling water of the gas engine 13 to radiate heat.
[0026]
Further, the control box 33 includes a controller for controlling the cogeneration system 100, a control device 40 having an inverter device for supplying generated power, and a temperature sensor 41 in the box.
[0027]
Further, the blower 34 (blower unit) blows air to cool each unit.
[0028]
The radiator 32 is disposed on one side of the radiator chamber 3, and the control box 33 is provided with a slit 42 on the front surface and a slit 43 on the rear surface of the case, and faces the radiator 32. The blower 34 is disposed immediately below the outlet 29 provided in the top panel 24 of the top of the heat radiating chamber 3.
[0029]
FIG. 2 is a schematic configuration block diagram of the cogeneration system of the embodiment. 2, the same parts as those in FIG. 1 are denoted by the same reference numerals.
[0030]
The cogeneration system 100 is roughly classified into a gas engine 13, a power transmission mechanism 51, a generator 14, an inverter 52, an engine controller 53, a load 60, a waste heat utilization unit 61, a distribution board 54, and a power integrator 55. , A main breaker 56, a load breaker 58, an inverter breaker 59, and a controller 110.
[0031]
The gas engine 13 burns a primary energy source 62 such as city gas under the control of the engine control unit 53, and drives the generator 14 via a power transmission mechanism unit 51 including a timing belt and a pulley. In parallel with this, the gas engine 13 supplies the generated heat to a waste heat utilization unit 61 such as a water heater (not shown) as waste heat.
[0032]
The generator 14 is driven by the gas engine 13 via the power transmission mechanism 51 and generates three-phase AC power.
[0033]
FIG. 3 is a detailed configuration diagram of the control device 40 and its periphery.
[0034]
The inverter 52 in the control device 40 converts the AC power supplied from the generator 14 into the same frequency as the commercial power 59 (for example, 50 Hz or 60 Hz) in accordance with the switching signal supplied from the IGBT drive circuit in the controller 110. To AC power. The output of the inverter 52 in the present embodiment realizes power quality that can be connected to the grid.
[0035]
In this case, the engine control unit 53 sets the rotation speed of the gas engine in accordance with the amount of power supplied to the load 60. Therefore, a signal corresponding to the rotation speed of the generator 14 or the rotation speed of the gas engine 13 is input to the controller 110 of the inverter 52.
[0036]
Here, an input circuit of a signal (AC waveform) having a frequency corresponding to the rotation speed of the generator 14 or the rotation speed of the gas engine 13 in the controller 110 will be described with reference to FIG.
[0037]
When a signal having a frequency corresponding to the number of revolutions of the generator 14 or the number of revolutions of the gas engine 13 is input via the input terminal TIN to the input circuit of the controller 110, the voltage dividing circuit composed of the resistor R1 and the resistor R2. The signal voltage is divided by the circuit, and the divided voltage corresponding to the signal terminal of the comparator 110A is applied.
[0038]
As a result, the comparator 110A compares the reference voltage Vref with the divided voltage, converts the reference voltage into a pulse signal having a pulse number corresponding to the rotation speed, and outputs the pulse signal to the photocoupler 110B.
[0039]
As a result, the pulse signal corresponding to the rotation speed of the generator 14 or the rotation speed of the gas engine 13 is electrically isolated from the input terminal TIN and the micro signal of the controller 110 in a state where noise is removed by the capacitor 110C. The data is input to the processor unit (MPU) 110D.
[0040]
As a result, the MPU 110D grasps the number of revolutions of the generator 14 or the number of revolutions of the gas engine 13 by counting the number of pulses of the pulse signal.
[0041]
When a signal corresponding to the rotation speed of the generator 14 or the rotation speed of the gas engine 13 is input and the rotation speed of the generator 14 or the rotation speed of the gas engine 13 is detected, the controller 110 determines the rotation speed of the generator 14. Alternatively, the supplied power amount corresponding to the rotation speed of the gas engine 13 is used as it is, or the power amount in consideration of a predetermined margin power amount from the supplied power amount corresponding to the rotation speed of the generator 14 or the rotation speed of the gas engine 13. The target output power amount of the inverter (the power amount of the matching power) is set, and the entire inverter 52 is controlled.
[0042]
More specifically, if the target output power is insufficient for the set target output power, the inverter 52 increases its own output current value to increase the supply power, and if the target output power is obtained, Will maintain that state.
[0043]
Here, the detailed operation of the inverter 52 will be described with reference to FIG.
[0044]
As shown in FIG. 3, the control device 40 has a controller 110 including a microcomputer. The controller 52 is connected to an inverter 52 via a built-in IGBT drive circuit (not shown).
[0045]
The inverter 52 has an electrolytic capacitor 116, and the electric power (three-phase AC power) generated by the generator 14 is converted into AC / DC by a three-phase (U-phase, V-phase, W-phase) bridge circuit 114. And output as DC power. The output DC power is boosted through a booster circuit 115 and then stored in an electrolytic capacitor 116.
[0046]
The booster circuit 115 includes a smoothing capacitor 115A, a boost reactor 115B, an IGBT 115C, and a diode 115D.
[0047]
The inverter 52 includes an inverter circuit 117. The inverter circuit 117 converts DC power supplied from the generator 14 into commercial power in accordance with a switching signal supplied from an IGBT drive circuit in the controller 110. The power is converted into AC power having the same frequency as the power supply (for example, 50 Hz or 60 Hz).
[0048]
The power converted into AC by the inverter circuit 117 is output to the distribution board 54 via the capacitor 118, the smoothing reactors 119 and 120, the inverter breaker 57, and the switches 121 and 122 (disconnected conductors).
[0049]
At this time, the AC power output from the inverter circuit 117 is output as a sine wave AC power from a PWM (Pulse Width Modulation) wave by passing through the capacitor 118 and the smoothing reactors 119 and 120.
[0050]
Controller 110 monitors terminal voltage V115A of electrolytic capacitor 115A, terminal voltage V116 of electrolytic capacitor 116, R-phase voltage, O-phase voltage, and T-phase voltage of the commercial power, and outputs the result from inverter circuit 117. The voltage, phase, and frequency of the AC power are controlled so as to match the voltage, phase, and frequency of the commercial power.
[0051]
On the other hand, the engine control unit 53 performs control so as to increase the rotation speed of the gas engine 13 and thus the generator 14 so that the amount of power supplied from the inverter 52 supplies the load power.
[0052]
Further, when the amount of power supplied from the inverter 52 is still insufficient even if the number of revolutions of the gas engine 13 and thus the generator 14 is increased, the engine control unit 53 obtains power from the commercial power source 59 to reduce the load. 60. In this case, the controller 110 detects the voltage, frequency, and phase of the commercial power supply 59 and controls the operation of the inverter 52 to match the output AC power with the power from the commercial power supply 59.
[0053]
Therefore, the maximum power supply capacity of the gas engine 13 including the inverter 52 can be set to be approximately equal to or smaller than the required power amount of the load to be supplied. Is used only when the power supplied from the inverter 52 is insufficient. As a result, the use efficiency of the cogeneration system is also improved, and if the power supply cost is lower than the power supply cost from the commercial power supply side, the total system operation cost can be reduced, and the system can be connected to the user. The merit of introducing a system power generation device is great.
[0054]
Further, as the inverter 52, an inverter that does not have a communication interface and can be controlled at high speed can be used, so that the system construction cost can be reduced.
[0055]
In the above, among the functions of the cogeneration system 100, the function as a system interconnection power generation device has been described. However, a waste heat utilization unit 61 as a heat recovery unit is provided on a cooling water path for cooling the gas engine 13. The hot water is supplied to the hot water supply tank 17 by recovering the heat, and the original function of the cogeneration system 100 is also provided.
[0056]
As described above, according to the present embodiment, an inverter having no communication interface function can be used as the inverter, and the construction cost of the cogeneration system can be reduced.
[0057]
In the above description, the configuration is adopted in which the rotational speed (operating state) of the gas engine or the generator is detected. However, the operating state is determined in consideration of both the rotational speeds (operating state) of the gas engine and the generator. However, it is also possible to configure to perform control.
[0058]
In the above description, the (rotor) rotation speed is directly detected as the operating state of the gas engine or the generator. However, the operating state is detected directly by detecting the rotation speed of the gas engine or the generator. However, the present invention is not limited to this. For example, it is configured to detect the operating state of the gas engine or the generator based on indirect information such as the number of revolutions detected or the amount of fuel supplied to the gas engine or the voltage generated by the generator. Is also possible.
[0059]
In the above description, the case where the internal combustion engine is used as the power source has been described. However, the present invention is not limited to this. For example, the invention can be applied to an external combustion engine.
[0060]
【The invention's effect】
According to the present invention, when detecting operation information that is information on the operation state of an engine or a generator, and converting the power obtained by power generation into matched power that is power that is matched with commercial power, based on the operation information, Since the power amount of the matching power to be generated is set, the power amount of the matching power to be generated can be directly set, an inverter without a communication interface function can be used, and the system construction cost is reduced. Reduction can be achieved.
[Brief description of the drawings]
FIG. 1 is a partially cutaway view of a cogeneration system according to an embodiment.
FIG. 2 is a schematic configuration block diagram of a cogeneration system of the embodiment.
FIG. 3 is a detailed configuration diagram of a control device 40 and its periphery.
FIG. 4 is an explanatory diagram of an input circuit of a signal (AC waveform) having a frequency corresponding to the rotation speed of a generator or a gas engine in a controller.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Machine room 2 Heat storage room 3 Radiation room 13 Gas engine (internal combustion engine)
14 Generator 52 Inverter 53 Engine control unit 54 Distribution board 55 Power integrator 56 Main breaker 57 Inverter breaker 58 Load breaker 59 Commercial power supply 100 Cogeneration system 110 Controller

Claims (7)

An engine and a grid-connected power generator having a generator driven by the engine and generating power,
An operation information detection unit that detects operation information that is information about an operation state of the engine or the generator,
Upon converting the power obtained by the power generation into matched power that is power matched with commercial power, a power amount setting unit that sets a power amount of the matched power to be generated based on the operation information,
A grid-connected power generator comprising: An engine, a grid-connected power generator including: a generator that is driven by the engine to generate power; and an inverter unit that converts power obtained by the power generation into matched power that is power matched with commercial power,
An operation information detection unit that detects operation information that is information about an operation state of the engine or the generator,
Upon converting the power obtained by the power generation into matched power that is power matched with commercial power, a power amount setting unit that sets a power amount of the matched power to be generated based on the operation information,
A grid-connected power generator comprising: 3. The grid-connected power generator according to claim 1, wherein the operation information is information on a rotation speed of a rotor of the engine or the generator. 4. The grid-connected power generator according to any one of claims 1 to 3,
The grid-connected power generator according to claim 1, wherein the operating state of the engine is set based on a set amount of supplied power. An engine, and a control method of a system interconnection power generation device including a generator driven by the engine and generating power,
An operation information detection step of detecting operation information that is information on an operation state of the engine or the generator,
Upon converting the power obtained by the power generation into matched power that is power matched with commercial power, a power amount setting step of setting a power amount of the matched power to be generated based on the operation information,
A method for controlling a grid-connected power generation device, comprising: The control method of the grid-connected power generator according to claim 5,
The method according to claim 1, wherein the operation information is information on a rotation speed of a rotor of the engine or the generator. In the control method of the grid-connected power generation device according to claim 5 or 6,
A method for controlling a grid-connected power generator, comprising an engine operating state setting step of setting an operating state of the engine based on a set amount of supplied power.

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