JP3415429B2 - Inverter device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an inverter device capable of converting DC power into AC power and connecting the AC power to the grid to output the power, and particularly to the output of an independent operation without using a transformer. It is possible to output in a method different from the method,
The present invention also relates to an inverter device in which the starting current of the load can be reduced to drive a transformer, a motor, or the like.

[0002]

2. Description of the Related Art FIG. 18 is a block diagram showing a typical configuration example of a conventional inverter device of this type.

In FIG. 18, the DC power of the DC power supply 1 is converted into desired AC power by the inverter bridge 2, and this power is output by being connected to the three-phase three-wire system 3.

The inverter bridge 2 includes three sets of half bridge circuits 4 to 4 connected between the positive electrode and the negative electrode of the DC power source 1.
6, the half-bridge circuit 4 connects the switch 7 and the switch 8 in series, the half-bridge circuit 5 connects the switch 9 and the switch 10 in series, and the half-bridge circuit 6 connects the switch 11 and the switch 12 in series. Connect and configure each.

Here, as the switches 7 to 12, it is general to use a semiconductor switch such as an IGBT to which an antiparallel diode is added.

On the other hand, the reactors 13 to 15 are connected to the system side of the bridge output points of the half bridge circuits 4 to 6, and the current detectors 16 to 18 for detecting the currents of the reactors 13 to 15 are further connected to the system side. .

On the DC side of the inverter bridge 2,
By connecting the capacitors 19 and 20 having a sufficiently large capacity in series, two DC power supplies required for the half bridge circuits 4 to 6 are secured. Then, the two DC power supplies serve as input power supplies common to the half bridge circuits 4 to 6.

Each of the half bridge circuits 4 to 6 generates an AC voltage between the middle point of the capacitors 19 and 20 and the bridge output point. Then, this AC voltage is used as a PWM waveform,
By switching at high frequency, reactors 13-15
A relatively smooth current can be applied to, but current ripple due to switching is superimposed.

Therefore, in order to reduce the outflow of the ripple current to the system 3, the capacitors 21 to 21 are provided between the midpoint of the capacitors 19 and 20 and the system side of each of the current detectors 16 to 18.
23 is connected.

On the other hand, the control of the output current is carried out in the current controllers 27 to 29 based on the reference signals from the output reference generators 24 to 26 and the current detection signals from the current detectors 16 to 18.

Since the sum of the instantaneous values of the output current of the device is zero, the sum of the instantaneous values of the reference signals from the output reference generators 24 to 26 also needs to be zero.

The current controllers 27 to 29 have, for example, a proportional-plus-integral control function and output an output command signal.

The PWM modulators 30 to 32 generate a PWM signal from the output command signal, the PWM modulator 30 switches 7 and 8, the PWM modulator 31 switches 9 and 10, P.
The WM modulator 32 drives the switches 11 and 12, respectively.

When there is a power failure in the system, the system is not interconnected and a voltage of fixed frequency and fixed amplitude is output as an independent operation.
Further, the output section has an interconnection switch 33 and an independent switch 34.
To provide.

The interconnection switch 33 is turned on during interconnection operation,
It will be disconnected during self-sustaining operation. In addition, the switch 34 for independence,
It is turned on during self-sustaining operation, but if it is turned on during interconnection operation, the interconnection system is output.

On the other hand, in order to control the voltage during self-sustaining operation,
Voltage detector 3 for detecting each voltage of capacitors 21-23
5 to 37 and voltage controllers 38 to 40 are provided, and each voltage of the capacitors 21 to 23 corresponding to the output phase voltage is automatically controlled according to the reference signal from the output reference generators 24 to 26.

The voltage controllers 38 to 40 have, for example, a proportional-integral control function, output an output command signal, and input it to the PWM modulators 30 to 32.

The switching between the self-sustaining operation and the interconnection operation is performed by the operation mode setting device 41, and the amplitude setting of the output reference generators 24 to 26 and the PWM modulators 30 to 32 are performed.
Select the input signal to.

In the case of three-phase output, the reference signals from the output reference generators 24 to 26 are generally sine waves whose phases are shifted by 120 degrees.

Therefore, the sine wave generator 42 is provided and its output signal is inputted to the phase shifter 43 which advances the phase by 120 degrees.

Further, the phase shifter 44 which advances the output signal from the phase shifter 43 by 120 degrees by another phase.
To enter.

As a result, the output signals from the sine wave generator 42, the phase shifter 43, and the phase shifter 44 become sine waves whose phases are shifted by 120 degrees. The direction in which the phase is shifted depends on the phase order of the system voltage.

During the interconnection operation, it is necessary to synchronize the output signal from the sine wave generator 42, which is the waveform reference of the output current, with the system 3.

Therefore, the voltage signal from the system voltage detector 45 is input to the synchronizing circuit 46 in the sine wave generator 42. The synchronization circuit 46 includes an operation mode setter 41
The output signal is also input from the system, and the synchronizing signal is generated based on the voltage signal from the system voltage detector 45 during the interconnection operation.
At the time of self-sustaining operation, a fixed frequency synchronizing signal irrelevant to the state of the system 3 is generated.

The output reference generators 24 to 26 receive the output signals from the sine wave generator 42, the phase shifter 43, and the phase shifter 44, respectively.
26 to 26, the amplitude is switched and set according to the output signal from the operation mode setter 41.

FIG. 19 is a block diagram showing a configuration example of the output reference generators 24-26.

In FIG. 19, there are an interconnection amplitude setting device 47 and an independent amplitude setting device 48, and the operation mode setting device 41.
The selector 49 selects the output signal of one of the amplitude setters 47 or 48 based on the output signal from the.

Here, the setting of the interconnection amplitude setting device 47 is as follows.
The output reference generators 24 to 26 have arbitrary same values, and the amplitude setting device 48 for self-sustaining is set so that the output of the self-sustaining operation is approximately the same as the voltage value of the interconnection system. Two
4 to 26 set the same value. Then, the selected amplitude signal is multiplied by the multiplier 50 and becomes the outputs of the output reference generators 24 to 26.

FIG. 20 is a block diagram showing a configuration example of the PWM modulators 30-32.

In FIG. 20, PWM modulators 30 to 32 are provided.
Then, based on the output signal from the operation mode setter 41, the selector 51 determines whether to use the output signal from the current controllers 27 to 29 or the output signal from the voltage controllers 38 to 40. The modulator 52 is selected, PWM modulation is performed by the modulator 52, and a drive signal is generated by the drive circuit 53.

[0031]

By the way, as shown in FIG.
In the conventional inverter device shown in (1), the number of phases and the voltage of the output in the self-sustained operation are the same as those in the interconnection.
Since the output of the self-sustaining operation has many purposes to be used as an emergency power source in the event of a disaster, it is assumed that a general electric product is used as a load.

Many loads use AC 100V as a power source, and cannot be used as they are if the interconnection system and the self-sustained operation output are three-phase 200V. For this reason, in many cases, a Scott transformer is provided in the self-sustained operation output circuit to convert the electric power of the three phases into an electric system for converting the electric power of the three phases into 100V.

However, since the transformer is a relatively large device, there is a problem that the conversion device becomes large.

Even if the system 3 at the time of interconnection is a three-phase three-wire 200V, it is disconnected from the interconnection system at the time of self-sustaining operation. Therefore, if the inverter is provided with that function, an arbitrary electric system and voltage value can be output. Is possible. And single phase 100V
In order to utilize the load of the
A method of setting 0 V or 100/200 V of single-phase three-wire is conceivable.

On the other hand, the output of the self-sustaining operation may be connected to a load such as a transformer or a motor which requires a relatively large current at the time of starting. In this case, a current exceeding the output capacity of the inverter may be required.

In order to operate the transformer load while suppressing the starting current, there is a method of gradually increasing the output voltage of the self-sustained operation at the time of starting from a low voltage to a predetermined voltage.

In order to start the motor load,
There is a method of increasing the frequency from a low frequency to a predetermined frequency as the voltage increases.

If the interconnection system and the self-sustained operation output have different electric systems and voltages, it is necessary to prevent the system voltage during interconnection operation from occurring in the self-sustained operation output. For this purpose, it is necessary to insert a switchgear into the self-sustained operation output section so that the switchgear will not be turned on during interconnection operation, and at the same time, when starting the self-sustaining operation, the switchgear can be turned on when necessary. There must be.

When the switchgear is electrically driven to open and close, its power supply is required. Here, it is the simplest to open and close the switchgear by using the self-sustained operation output of the inverter as it is, but when gradually increasing the voltage at startup, until the voltage rises to some extent. It will not be possible to make and drive.

On the other hand, if the power supply circuit for driving the switchgear is separately provided, the switchgear can be turned on under arbitrary conditions. However, when the self-sustained operation is used, the system 3 may be in a power failure state. In many cases, the energy source that can be used for opening and closing drive in the long term is limited.

Further, when there are a plurality of motor loads, it is necessary to have a function of gradually increasing the voltage or frequency when starting each motor. If the output of the self-sustaining operation is common to multiple motors, and if one motor is being driven while another motor is being driven, it is necessary to temporarily lower the voltage or frequency. The motor will stop.

Further, in the case of a plurality of motor loads, a single inverter cannot handle it, and it is necessary to drive each motor by using a plurality of inverters.

The object of the present invention is to enable the output of the self-sustained operation to be output by a method different from the electric method of the interconnection system without using a transformer, and also to reduce the starting current of the load so that the output of the transformer or the motor is reduced. An object is to provide an inverter device capable of driving.

[0044]

In order to achieve the above object, the invention of claim 1 converts DC power into AC power.
Has an inverter that can be connected to the grid and output.
The interconnected operation that is connected to the
In the switchable inverter device,
Branch the AC side into multiple circuits and
One of the circuits is connected to the system as an interconnection output unit.
Switchgear between the interconnection output and the grid receiving point
The other branch circuit among multiple branch circuits is self-contained
Part can be connected to the load via a switchgear,
When a switchgear is installed between the power unit and the grid power receiving point
In this case, the opening / closing device of the self-sustained output unit is prevented from being closed .

[0045]

[0046]

Therefore, in the inverter device according to the first aspect of the present invention, when the switchgear provided between the interconnection output unit and the grid power receiving point is turned on, the switchgear of the self-sustained output unit is prevented from being turned on. This can drive a self-sustaining load different from the electrical system of the interconnection system, or reduce the start-up current of the motor load during self-sustaining operation. It is possible to prevent joining.

Further, in the invention of claim 2 , DC power is supplied.
Inverter that can be converted to AC power and connected to the grid for output
Has a switch and is connected to the grid and disconnected from the grid.
In an inverter device capable of switching between independent operation , the AC side of the inverter is branched into a plurality of circuits, and a switchgear is provided in each of the plurality of branch circuits.
One branch circuit of the plurality of branch circuits can be connected to the system via the switchgear as an interconnection output unit, and the other branch circuit of the plurality of branch circuits can be connected to the load via the switchgear as an independent output unit. When the switchgear of the interconnection output unit is turned on and the system is interconnected, the switchgear of the self-sustained output unit is prevented from being turned on.

Therefore, in the inverter device according to the second aspect of the present invention, when the switchgear of the interconnection output section is turned on to operate in an interconnected manner with the system, the switchgear of the self-sustained output section is prevented from being turned on. , It is possible to drive a self-sustaining load that is different from the electric system of the interconnection system, or to reduce the starting current of the motor load during self-sustaining operation.
It is possible to prevent a voltage of a system different from the drive voltage of the load from being applied.

On the other hand, in the invention of claim 3 , the above-mentioned claim 1
In the inverter device configured by using multiple inverter devices described in, it is possible to connect the interconnection output parts of each inverter device collectively to the same system, and receive power from the point that the system side switchgear is integrated. Set up to the point,
When the switchgear is turned on, the switchgear of the independent output units of all the inverters is prevented from being turned on.

Therefore, in the inverter device according to the third aspect of the present invention, when the switchgear provided between the collective connection point of each inverter device body and the power receiving point is turned on, the self-sustained output parts of all the inverters. By blocking the opening and closing of the switchgear, it is possible to drive a self-sustaining load that is different from the electrical system of the interconnection system, or to reduce the starting current of the motor load during self-sustaining operation. It is possible to prevent a voltage of a system different from the drive voltage from being applied.

In the invention of claim 4 , the above-mentioned claim 1 is adopted.
Alternatively, in an inverter device configured by using a plurality of inverter devices of the invention of claim 2, the interconnection output parts of respective inverter device bodies can be connected to the same system, and one or more inverters can be separated from the system. When performing the self-sustaining operation, a command to start the operation of the inverter that performs the self-sustaining operation is individually given.

Therefore, in the inverter device according to the fourth aspect of the present invention, during the self-sustained operation of one or more inverters,
By giving a command to start the operation of the inverter individually, it is possible to drive a self-sustaining load different from the electric system of the interconnection system, or to reduce the starting current of the motor load during self-sustaining operation, Motor loads can be individually shut down.

Furthermore, in the invention of claim 5 , in the inverter device of the invention of claim 3 or 4, the solar battery power source corresponding to the number of a plurality of inverters in the inverter device main body is provided on the DC side. Two DC power supplies of constant voltage are input, and each DC side of the inverter that is connected to the grid to operate is connected to an individual solar cell power supply. It is designed to be connected to a battery power supply and a constant voltage DC power supply.

Therefore, in the inverter device according to the fifth aspect of the present invention, the solar battery power source and one constant voltage direct current power source corresponding to the number of a plurality of inverters in the inverter device body are input to the DC side, and the interconnection is performed. By connecting each DC side of the operating inverter to an individual solar cell power source, and connecting the DC side of the self-sustaining inverter collectively to the solar cell power source / constant voltage DC power source, the interconnection system can be electrically connected. It can drive different self-sustaining loads, or reduce the starting current of the motor load during self-sustaining, can stop multiple motor loads in self-sustaining individually, and maximize the power generation capacity of the solar cell during interconnection. It can be taken out, and the DC power supply during independent operation can be stabilized.

On the other hand, according to the invention of claim 6 , an inverter capable of converting the DC power of the DC power supply into AC power and outputting the AC power in an interconnected manner, and means for controlling the output current of the inverter to a desired value, When the inverter is operated by connecting it to the grid, the output current of the inverter is controlled to a desired value, and the inverter is self-sustained by disconnecting from the grid. When operating, in an inverter device in which the output voltage of the inverter is controlled to a desired value and the output voltage at the start of operation is gradually increased to a predetermined value, the AC side of the inverter is divided into two circuits. When branching, one side of the branch circuit is provided with a switchgear to connect to the system, and the other branch circuit is connected to a load.When starting operation of the load, the switchgear is disconnected and connected to the system. Do not start self-sustaining operation, gradually apply voltage to the load, synchronize the system voltage with the output voltage after reaching the system voltage value, and then switch on the switchgear and control the output current. I'm trying to switch.

Therefore, in the inverter device according to the sixth aspect of the present invention, the starting current of the motor load is reduced during self-sustaining operation by gradually increasing the output voltage at the start of operation when the inverter is operating independently. At the start of load operation, the switchgear is disconnected, self-sustained operation is started, voltage is gradually applied to the load, and after the output voltage reaches the system voltage value, it is synchronized with the system voltage. By turning on the switchgear and switching to the interconnection operation that controls the output current, the starting current of the motor load can be reduced during self-sustaining operation, and the inverter can be switched to the interconnection operation while the motor load is operating. be able to.

According to the invention of claim 7 , the above-mentioned claim 1 is used.
Or one or more inverter devices according to the invention of claim 2 ,
In the inverter device constituted by using the above one of the inverter apparatus for outputting a predetermined constant voltage in the case of self-sustaining operation without system and interconnection, the claim 1 or claim
In the inverter device main body of the second invention, the switchgear of the branch circuit that outputs a self-sustaining output is a device that electrically opens and closes, and the drive power of the switchgear outputs a predetermined constant voltage when operating independently. I'm trying to get it from the output.

Therefore, in the inverter device according to the seventh aspect of the invention, the inverter device main body according to the first or second aspect of the invention uses the branch circuit switchgear for producing a self-sustaining output as an electrical switchgear to drive the same. By obtaining electric power from the output of the inverter unit that outputs a predetermined constant voltage during self-sustaining operation, it is possible to drive a self-sustaining load different from the electrical system of the interconnection system, or reduce the starting current of the motor load during self-sustaining operation. Besides, the self-sustained operation output in the device can be used as the drive power source for the self-sustained switchgear during self-sustaining operation, and the power supply device for driving the switchgear can be omitted.

[0060]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

(First Embodiment) FIG. 1 is a block diagram showing a configuration example of an inverter device according to the present embodiment. The same parts as those in FIG. 18 are designated by the same reference numerals and the description thereof will be omitted. , Here, only different parts will be described.

That is, the inverter device of the present embodiment has a structure in which the phase shifter 54 is added to the structure shown in FIG. 18, as shown in FIG.

The phase shifter 54 shifts the output signal from the sine wave generator 42 by 180 degrees and outputs it to the output reference generator 26.

The system side is a three-phase three-wire system, and the three wires are R
These are called lines, S lines, and T lines.

On the other hand, the output reference generator 25 is constructed as shown in the block diagram of FIG.

In FIG. 2, the same parts as those in FIG. 19 are designated by the same reference numerals, and the description thereof will be omitted. Here, only different parts will be described.

That is, the output reference generator 25 is as shown in FIG.
19, the amplitude setting device 48 for self-sustaining is omitted and the signal selected by the selector 49 is fixed to zero when the output signal from the operating mode setting device 41 is in the self-sustaining operating mode.

The output reference generators 24 and 26 are the same as those shown in FIG.
The block diagram of FIG.

In FIG. 3, the same parts as those in FIG. 19 are designated by the same reference numerals, and the description thereof will be omitted. Here, only different parts will be described.

That is, the output reference generators 24, 26
As shown in FIG. 3, a 100V setting device 56 is provided in place of the self-sustaining amplitude setting device 48 in FIG. 19 to output an amplitude signal such that the output during self-sustaining operation is 100V.

As the sine wave reference, the output signal from the phase shift circuit 54 and the output signal from the phase shift circuit 54 are input.

The selector 55 interlocks with the selector 49 and outputs the output signal from the phase shift circuit 44 as a signal to be input to the multiplier 50 when the output signal from the operation mode setter 41 is in the interconnection mode. If the signal from the operation mode setting unit 41 is in the interconnection mode, the output signal from the phase shift circuit 54 is selected as the signal to be input to the multiplier 50.

Next, the operation of the inverter device of the present embodiment configured as described above will be described.

Since the operation during the interconnection operation is the same as that of the conventional case shown in FIG. 18, the description thereof will be omitted here.

Phase shifter 5 newly provided for independent operation
The output signal from No. 4 is a signal whose polarity is inverted from that of the output signal from the sine wave generator 42, because the output signal from the sine wave generator 42 is output after being shifted by 180 degrees.

In the output reference generator 25 shown in FIG. 2, the zero signal is selected by the selector 49 in response to the output signal from the operation mode setting device 41 during the self-sustained operation. As a result, the output signal from the output reference generator 25 during self-sustaining operation also becomes zero, and as a result of the control by the voltage controller 39, the voltage of the capacitor 22 which is the output phase voltage is controlled to 0V.

In addition, the output reference generator 24 or 2 of FIG.
6, the output signal from the 100V setting device 56 controls the voltage of the output phase voltage of the capacitors 21 and 23 to 100V as a result of the control by the voltage controller 38 or 40.

In the output reference generators 24 and 26, during self-sustaining operation, the output signal from the operation mode setting unit 41 causes the selector 55 to input a sine wave as a signal to be input to the multiplier 50 as a sine wave reference. The output signal from the wave generator 42 or the phase shift circuit 54 is selected.

The output signal from the phase shifter 54 has the opposite polarity to the output signal from the sine wave generator 42. As a result, the output signal from the output reference generator 26 during the self-sustaining operation has the opposite polarity to the output signal from the output reference generator 24, and as a result of the control by the voltage controller 40, the voltage of the capacitor 23, which is the output phase voltage. Is controlled to 100 V, which is the reverse polarity of the capacitor 21.

As a result, when the output is interconnected, the voltage between the RSs during the self-sustaining operation is 100V, and the voltage between the TSs during the interconnection is 1 with the opposite polarity.
Controlled to 00V, the output during self-sustained operation is single-phase 3-wire 100
It becomes / 200V.

As described above, in carrying out the self-sustaining operation, it is possible to output the voltage of the electric system different from the three-phase system voltage applied to the conversion device at the time of interconnection without changing the wiring of the main circuit portion.

As described above, in the inverter device of the present embodiment, the output currents of at least two sets of half bridge circuits are controlled to desired values during the interconnection operation of the inverters, and one set is set during the independent operation of the inverters. The output voltage of the half bridge circuit is controlled to zero voltage, and the output voltages of the two sets of half bridge circuits are controlled to values of the same amplitude which are 180 degrees out of phase with each other. It is possible to drive different independent operation loads.

(Second Embodiment) The overall configuration of the inverter device according to the present embodiment is the same as in the case of FIG. 18, and the output reference generators 24 to
Only the configuration of 26 differs from that of FIG.

FIG. 4 is a block diagram showing a configuration example of the output reference generators 24 to 26 according to the present embodiment, and FIG.
The same parts as those of the above are given the same reference numerals and the description thereof will be omitted, and only different parts will be described here.

That is, the output reference generators 24 to 26
As shown in FIG. 4, a 100V setting device 56 is provided in place of the self-standing amplitude setting device 48 in FIG.

The 100V setting device 56 outputs an amplitude value such that the output during the self-sustaining operation is 100V.

Next, the operation of the inverter device of the present embodiment configured as described above will be described.

Since the operation during the interconnection operation is the same as that in the conventional case shown in FIG. 18, the description thereof will be omitted here.

Since the waveform reference of the sine wave input to the output reference generators 24 to 26 is the same as that in the case of FIG. 18,
The output signals from the output reference generators 24 to 26 are sine waves having a phase difference of 120 degrees with each other.

In the independent operation, the output reference generators 24 to 26
The voltage amplitude signal selected in the
Therefore, as a result of the control by the voltage controllers 38 to 40,
The voltage of the capacitors 21 to 23, which is the output phase voltage, is 10 each
It is controlled to 0V.

As a result, the output voltage during the self-sustaining operation is three-phase three-wire 100V.

As described above, in carrying out the self-sustaining operation, it is possible to output an electric system voltage different from the three-phase system voltage applied to the converter during interconnection without changing the wiring of the main circuit section.

As described above, in the inverter device of the present embodiment, the output currents of at least two sets of half bridge circuits are controlled to desired values during the interconnection operation of the inverters, and three sets are set during the independent operation of the inverters. Since the output voltage of the half bridge circuit is controlled to a voltage having a phase difference of 120 degrees with a desired amplitude different from the voltage value of the interconnection system, a self-sustained operation load different from the electrical system of the interconnection system can be applied. It becomes possible to drive.

(Third Embodiment) FIG. 5 is a block diagram showing a configuration example of an inverter device according to the present embodiment. The same parts as those in FIG. 18 are designated by the same reference numerals and the description thereof will be omitted. , Here, only different parts will be described.

That is, as shown in FIG. 5, the inverter device of this embodiment has a configuration in which a self-sustained operation switch 57 and a ramp generator 58 are added to FIG.

The self-sustained operation switch 57 outputs a self-sustained operation signal to the ramp generator 58.

The lamp generator 58 has an output signal of 1 when the output signal from the self-sustained operation switch 57 is off, and once when the output signal from the self-sustained operation switch 57 is turned on, it temporarily becomes 0, and the ramp generator 58 has a predetermined time. By multiplying by 0, it increases linearly from 0 to 1 and outputs a signal holding 1 during the subsequent operation.

Then, the output signal from the ramp generator 58 is output to the output reference generators 24 to 26.

On the other hand, the output signal from the self-sustained operation switch 57 is also output to the operation mode setter 41, and the operation mode setter 41 determines whether it is the interconnection operation mode or the self-sustained operation mode and sends a signal to each part. give.

On the other hand, the output reference generators 24 to 26 are the same as those shown in FIG.
The block diagram of FIG.

In FIG. 6, the same parts as those in FIG. 19 are designated by the same reference numerals, and the description thereof will be omitted. Here, only different parts will be described.

That is, the output reference generators 24 to 26
As shown in FIG. 6, a multiplier 59 is newly added to FIG. 19 and the output signal from the ramp generator 58 is input from the outside.

The multiplier 59 multiplies the output signal from the independent amplitude setting device 48 and the output signal from the ramp generator 58, and outputs the amplitude signal.

The output signal from the multiplier 59 is selected as the amplitude reference of the output sine wave by the selector 49 during the self-sustained operation.

Next, the operation of the inverter device of the present embodiment configured as described above will be described.

Since the operation during the interconnection operation is the same as in the conventional case shown in FIGS. 18 and 19, the description thereof will be omitted here.

The amplitude reference at the start of the self-sustaining operation linearly increases from 0 to the output value of the self-sustaining amplitude setter 48 over a predetermined time, and after the predetermined time, becomes the output signal from the self-standing amplitude setter 48. It will be the same value.

The output signals of the output reference generators 24-26 are:
The product of this signal and a sine wave signal having a phase difference of 120 degrees from each other.

As a result of the control by the voltage controllers 38 to 40,
The voltage of the capacitors 21 to 23, which is the output phase voltage, gradually increases from 0 V to a predetermined value at the start of the self-sustained operation, and then becomes a constant three-phase voltage.

As described above, when the transformer is connected to the load for self-sustaining operation, the voltage of the transformer gradually increases, so that the generation of the rush current peculiar to the transformer can be prevented.

As described above, in the inverter device of the present embodiment, the output voltage at the start of operation when the inverter is operated in a self-sustaining manner is gradually increased to a predetermined value. It is possible to reduce the starting current.

(Fourth Embodiment) FIG. 7 is a block diagram showing a configuration example of an inverter device according to the present embodiment. The same parts as those in FIG. 5 are designated by the same reference numerals and the description thereof will be omitted. , Here, only different parts will be described.

That is, the inverter device of the present embodiment, as shown in FIG. 7, has the ramp generator 58 shown in FIG.
The output signal from is output not only to the output reference generators 24 to 26 but also to the sine wave generator 42.

On the other hand, the sine wave generator 42 is constructed as shown in the block diagram of FIG.

That is, the present sine wave generator 42 is similar to that shown in FIG.
As shown in, the synchronization circuit 46, the sine wave generator 60,
It is composed of a rated frequency setting device 61 and a multiplier 62.

The frequency of the sine wave generator 60 can be set from the outside, and the frequency of the output signal increases in proportion to the signal.

The rated frequency setting device 61 sets a signal having a fixed value corresponding to the rated frequency.

The multiplier 62 multiplies the output signal from the rated frequency setting unit 61 and the output signal from the ramp generator 58, and outputs a frequency signal.

The output signal from the multiplier 62 becomes an input signal to the sine wave generator 60, and the sine wave generator 60 outputs a sine wave having a frequency according to this input signal.

The synchronizing circuit 46 includes the operation mode setter 41.
From the grid voltage detector 45, the output signal from the system voltage detector 45, and the output signal from the multiplier 62 are input.

The synchronizing circuit 46 generates a synchronizing signal based on the output signal from the grid voltage detector 45 when the operation mode is the interconnection operation mode, and from the multiplier 62 when the operation mode is the self-sustaining operation mode. The sync signal is generated based on the frequency signal of and is output to the sine wave generator 60, respectively.

Next, the operation of the inverter device of the present embodiment configured as described above will be described.

The ramp generator 58 has an output signal of 1 when the output signal from the self-sustained operation switch 57 is off, and once when the output signal from the self-sustained operation switch 57 is turned on, it temporarily becomes 0, and the ramp generator 58 has a predetermined time. By multiplying by 0, it increases linearly from 0 to 1 and outputs a signal holding 1 during the subsequent operation.

Since the output signal from the ramp generator 58 is multiplied by the output signal from the rated frequency setting device 61, the frequency signal input to the sine wave generator 60 at the start of the self-sustaining operation is 0. To the rated frequency setting, it linearly increases over a predetermined time, and after the predetermined time, it becomes the same value as the output signal from the rated frequency setter 61.

The output signals from the sine wave generator 42 are finally output to each other by the phase shifters 43 and 44.
Three sets of sine wave signals having a phase difference of degrees are input to the output reference generators 24-26.

As a result of the control by the voltage controllers 38 to 40,
The voltage of the capacitors 21 to 23, which is the output phase voltage, gradually increases from 0V to 100V at the start of the self-sustained operation, and the frequency also gradually increases from 0 to the rated frequency.

Further, regarding the voltage amplitude and the frequency, the ramp generator 61 is commonly used, so that the starting current peculiar to the motor is reduced and the ratio of the voltage and the frequency is made constant, so that the motor can be operated. Can be started.

On the other hand, since the output signal from the ramp generator 58 input to the sine wave generator 42 during the interconnection operation is 1, the frequency signal input to the sine wave generator 60 is the rated frequency setter. It has the same signal value as the output signal from 61. Therefore, the output signal from the sine wave generator 42 is
It becomes a sine wave of the rated frequency.

Since the operation other than this is the same as that in the conventional case shown in FIG.
The description is omitted here.

As described above, in the inverter device according to the present embodiment, in the period in which the output voltage at the start of operation when the inverter is operated in a self-sustaining operation is gradually increased to a predetermined value,
Since the output frequency of the inverter is also gradually increased to a predetermined value, it is possible to reduce the starting current of the motor load during self-sustaining operation.

(Fifth Embodiment) This embodiment can be applied to any of the first to fourth embodiments, but here, the present embodiment is not limited to the first embodiment. The case where it is applied will be described.

FIG. 9 is a block diagram showing a configuration example of the inverter device according to the present embodiment. The same parts as those in FIG. 1 are designated by the same reference numerals and the description thereof will be omitted. Here, only different parts will be described. .

System 3 indicates the power receiving point.

That is, in the inverter device of the present embodiment, as shown in FIG. 9, the interconnection output switch of the device is provided with the interconnection switch 33 between the device and the power receiving point.

Further, the self-sustaining switch 3 is provided at the self-sustaining output section.
4 is provided.

The interconnection switch 33 is a switch that is closed only during interconnection operation, and is, for example, a manually operated switch.

The interconnection switch 33 includes the interconnection switch 33.
Auxiliary contact 65 that is closed only when is disconnected,
The status signal is input to the inverter.

The self-sustaining switch 34 is a switch having an operation coil 63 with a structure for electrically opening and closing, and a drive circuit 64.
Is provided, and the self-sustaining switch 34 is in the closed state only when the voltage is applied to the operation coil 63.

The voltage of the drive circuit 64 is generated when the self-sustained operation switch 57 is a signal indicating the self-sustained operation.

On the circuit consisting of the drive circuit 64 and the operation coil 63, the circuit of the auxiliary contact 65 of the interconnection switch 33 which is closed only when the interconnection switch 33 is disconnected is inserted in series. ing.

Next, the operation of the inverter device of the present embodiment configured as described above will be described.

During the interconnection operation, the interconnection switch 33 is closed to operate. At this time, the auxiliary contact 65 of the interconnection switch 33 is opened. In this state, even if a voltage is generated in the drive circuit 64, no voltage is applied to the operation coil 63. During interconnection operation, the voltage of grid 3 is
However, this voltage is not generated in the self-sustained operation output section because the self-sustained switch 34 cannot be closed.

On the other hand, during the self-sustaining operation, the interconnection switch 33 is disconnected and operated. At this time, the auxiliary contact 65 of the interconnection switch 33 is closed. In this state, the drive circuit 64
Since the voltage generated at is applied to the operation coil 63, the self-standing switch 34 can be turned on.

As described above, it is possible to prevent system voltages different in voltage or electric system from being generated in the self-sustained operation output section due to malfunction of the self-sustaining switch 34 or the like.

As described above, in the inverter device of the present embodiment, when the interconnection switch 33 provided between the interconnection output unit and the system power receiving point is turned on, the self-sustained output unit is opened / closed for independence. Since it is arranged to prevent the device 34 from being turned on, it is possible to drive a self-sustaining load different from the electrical system of the interconnection system, or to reduce the starting current of the motor load during self-sustaining operation. It is possible to prevent the voltage of the system 3 different from the drive voltage of the load from being applied.

(Sixth Embodiment) This embodiment can be applied to any of the first to fourth embodiments, but here, the present embodiment is not limited to the first embodiment shown in FIG. The case where it is applied will be described.

FIG. 10 is a block diagram showing a configuration example of the inverter device according to the present embodiment. The same parts as those in FIG. 1 are designated by the same reference numerals and the description thereof will be omitted, and only different parts will be described here. .

That is, in the inverter device of the present embodiment, as shown in FIG.
An interconnection switch 33 is provided.

The self-sustaining output section has a self-sustaining switch 3
4 is provided.

The interconnection switch 33 is a switch that is closed only during interconnection operation, and is, for example, a manually operated switch.

The interconnection switch 33 includes the interconnection switch 33.
Auxiliary contact 65 that is closed only when is disconnected,
The status signal is input to the inverter.

The self-sustaining switch 34 is a switch having an operation coil 63 with a structure for electrically opening and closing, and a drive circuit 64.
Is provided so that the independent switch 33 is turned on only when the voltage is applied to the operation coil 63.

The voltage of the drive circuit 64 is generated when the self-sustained operation switch 57 is a signal indicating the self-sustained operation.

On the circuit consisting of the drive circuit 64 and the operation coil 63, the circuit of the auxiliary contact 65 of the interconnection switch 33 which is closed only when the interconnection switch 33 is disconnected is inserted in series. ing.

Next, the operation of the inverter device of the present embodiment having the above configuration will be described.

During the interconnection operation, the interconnection switch 33 is closed to operate. At this time, the auxiliary contact 65 of the interconnection switch 33 is opened. In this state, even if a voltage is generated in the drive circuit 64, no voltage is applied to the operation coil 63. During interconnection operation, the voltage of grid 3 is
However, this voltage is not generated in the self-sustained operation output section because the self-sustained switch 34 cannot be closed.

On the other hand, during the self-sustaining operation, the interconnection switch 33 is disconnected and operated. At this time, the auxiliary contact 65 of the interconnection switch 33 is closed. In this state, the drive circuit 64
Since the voltage generated at is applied to the operation coil 63, the self-standing switch 34 can be turned on.

As described above, it is possible to prevent system voltages different in voltage or electric system from being generated in the self-sustained operation output section due to malfunction of the self-sustained switch 34 or the like.

As described above, in the inverter device of the present embodiment, when the interconnecting switch 33 of the interconnecting output unit is turned on to perform the interconnected operation with the system, the independent switch 34 of the independent output unit is used. Since it is designed to prevent the power supply from being turned on, it is possible to drive a self-sustaining load different from the electrical system of the interconnection system, or to reduce the starting current of the motor load during self-sustaining operation. System 3 different from drive voltage
It is possible to prevent the application of the voltage.

(Seventh Embodiment) FIG. 11 is a block diagram showing a configuration example of an inverter device according to the present embodiment. The same parts as those in FIG. 9 are designated by the same reference numerals and the description thereof will be omitted. , Here, only different parts will be described.

That is, as shown in FIG. 11, the inverter device of the present embodiment includes a plurality of inverter devices (three in this example) having the same structure as the inverter device of the fifth embodiment shown in FIG. The inverter devices 66 to 68 are used.

The interconnection output parts of the inverter devices 66 to 68 are grouped together and connected to the system 3 via the interconnection switch 33 common to the inverter devices 66 to 68.

The interconnection switch 33 is a switch that is closed only during interconnection operation, and is, for example, a manually operated switch.

The interconnection switch 33 includes the interconnection switch 33.
Auxiliary contact 6 of the same function that closes only when the
9 to 71 are provided.

On the other hand, the self-sustaining switch 34 is provided at the self-sustaining output section of each of the inverter devices 66 to 68.

The self-sustaining switch 34 is a switch having an operation coil 63 with a structure for electrically opening and closing, and a drive circuit 64.
Is provided so that the independent switch 33 is turned on only when the voltage is applied to the operation coil 63.

The output signal from the operation mode setter 41 is input to the drive circuit 64, and the drive circuit 64 generates a voltage when the operation mode signal from the operation mode setter 41 indicates a self-sustaining operation.

In each of the inverter devices 66 to 68, the auxiliary contact 66 of the interconnection switch 33, which is closed only when the interconnection switch 33 is disconnected, is provided on the circuit consisting of the drive circuit 64 and the operation coil 63. The circuits of 68 are inserted in series.

Next, the operation of the inverter device of the present embodiment configured as described above will be described.

During the interconnection operation, the interconnection switch 33 is closed to operate. At this time, the auxiliary contacts 69-
71 is opened respectively. Then, in this state, even if a voltage is generated in the drive circuit 64 of each of the inverter devices 66 to 68, no voltage is applied to the operation coil 63. At the time of the interconnection operation, the voltage of the grid 3 is generated in the capacitors 21 to 23, but since the respective independent switch 34 cannot be turned on, this voltage is not generated at the independent operation output section.

On the other hand, during the self-sustaining operation, the interconnection switch 33 is disconnected and operated. At this time, the auxiliary contacts 69 to 71 of the interconnection switch 33 are closed. Then, in this state, the voltage generated in the drive circuit 64 of each of the inverter devices 66 to 68 is applied to the operation coil 63, so that the independent switch 34 can be turned on.

As described above, it is possible to prevent system voltages of different voltages or electric systems from being generated at the self-sustained operation output section due to malfunction of the self-sustained switch 34 or the like.

As described above, in the inverter device of the present embodiment, when the interconnection switch 33 provided between the collective connection point of the respective inverter devices 66 to 68 and the power receiving point is turned on, Since it is arranged to prevent the switch 34 for self-sustaining of the self-sustaining output part of the inverter of FIG.
It can drive a self-sustaining load that is different from the electric system of the interconnection system, or can reduce the starting current of the motor load during self-sustaining operation. In addition, a voltage of system 3 different from the drive voltage of the load is added to the self-sustaining load. Can be prevented.

(Eighth Embodiment) This embodiment can be applied to any of the fifth and sixth embodiments, but here, FIG.
The case of application to the sixth embodiment of No. 0 will be described.

FIG. 12 is a block diagram showing a configuration example of the inverter device according to the present embodiment. The same parts as those in FIG. 10 are designated by the same reference numerals and the description thereof will be omitted. Here, only different parts will be described. .

That is, as shown in FIG. 12, the inverter device according to the present embodiment includes a plurality of inverter devices (three in this example) having the same structure as the inverter device according to the sixth embodiment shown in FIG. The inverter devices 66 to 68 are used.

The interconnection output parts of the respective inverter devices 66 to 68 are connected to the common system 3. In addition, the self-sustained output units of the inverter devices 66 to 68 can be connected to individual loads.

Here, each of the inverter devices 66 to 68 is provided with a self-sustained operation switch 57, and when each self-sustained operation switch 57 is turned on, the output signal from the operation mode setter 41 becomes a signal indicating the self-sustained operation, and the output of each section is changed. The control is switched.

The self-sustained operation switch 57 of each of the inverter devices 66 to 68 is not interlocked between the devices.

Next, the operation of the inverter device of the present embodiment configured as described above will be described.

As an example, the inverter devices 66 and 67 will now be used.
In order to independently operate the inverter, the inverter devices 66, 67
The interconnection switch 33 of is disconnected. At this time, the auxiliary contact 65 of the interconnection switch 33 of the inverter devices 66 and 67 is closed. The operation state of the inverter device 68 may be any state including the interconnection operation.

When the self-sustained operation switch 57 is turned on, the output signal from the operation mode setter 41 becomes a signal indicating the self-sustained operation, and the control of each part is switched. As a result, a voltage is generated in the drive circuit 64 of the self-sustaining switch 34, and the self-sustaining operation is started.

Independent operation switch 5 of the inverter device 66
7 is turned on, the drive circuit 64 of the inverter device 66
Voltage is generated in the inverter device 66, and the independent switch 3 of the inverter device 66 is generated.
4 is turned on, and the self-sustained operation load of the inverter device 66 is driven. When the self-sustained operation switch 57 of the inverter device 67 is further turned on from this state, a voltage is generated in the drive circuit 64 of the inverter device 67, the self-sustaining switch 34 of the inverter device 67 is turned on, and the self-sustained operation of the inverter device 67 is started. The operating load is driven.

At this time, the state of the self-sustained operation output of the inverter device 66 and the operating state of the inverter device 68 do not change.

As described above, a plurality of inverter devices 66 are provided.
Up to 68 can be individually selected for the interconnected operation and the self-sustaining operation, and the load can be individually driven especially for the self-sustaining operation load. Further, the motor load or the like needs to change the voltage or the frequency for starting, so that when a certain motor is started, it does not affect the operating states of other motors.

As described above, in the inverter device of this embodiment, when one or more inverters are operated independently,
Since the commands to start the operation of the inverter are given individually, it is possible to drive a self-sustaining load that is different from the electrical system of the interconnection system, or to reduce the starting current of the motor load during self-sustaining operation. It is possible to individually stop the operation of multiple motor loads.

(Ninth Embodiment) This embodiment can be applied to any of the seventh or eighth embodiments, but here, FIG.
The case of application to the eighth embodiment of No. 2 will be described.

FIG. 13 is a block diagram showing a configuration example of the inverter device according to the present embodiment. The same parts as those in FIG. 12 are designated by the same reference numerals and the description thereof will be omitted. Here, only different parts will be described. .

That is, in the inverter device of this embodiment, as shown in FIG. 13, the solar cells 72 to 72 for the inverter devices are used as the DC power sources of the inverter devices 66 to 68.
74 and a battery 75 common to each inverter device.

A solar cell 72 is connected to the inverter device 66 as the DC power supply 1. Further, the battery 75 is connected via the switch 76.

A solar cell 73 is connected to the inverter device 67 as the DC power supply 1. Further, the battery 75 is connected through the switch 77.

A solar cell 74 is connected to the inverter device 68 as the DC power supply 1. Further, the battery 75 is connected via the switch 78.

The switches 76 to 78 are turned on when the self-sustained operation switch 57 of the inverter devices 66 to 68 indicates the self-sustained operation.

Next, the operation of the inverter device of the present embodiment configured as described above will be described.

Of the inverter devices 66 to 68, the inverter device which operates independently is connected to the battery via the switch.

For example, when the inverter device 66 is operated independently, the switch 76 is turned on and the battery 75 is connected.

Further, for example, the inverter devices 66 and 67
When operating independently, the switches 76 and 77 are turned on and the battery 75 is connected.

As an example, when the inverter device 66 is operated independently and the inverter devices 67 and 68 are interconnected, the switch 76 is turned on and the switches 77 and 78 are disconnected.

At this time, the DC power supplies of the inverter devices 67 and 68 are the solar cells 73 connected to the respective inverter devices.
74, which are interconnected.

In addition, the DC power source 1 of the inverter device 66
Serves as a parallel power source for the solar cell 72 and the battery 75.

When the self-sustained operation load of the inverter device 66 for self-sustaining operation exceeds the power generation capacity of the solar cell 72,
The power exceeding this amount is supplied from the battery 75.

It is difficult for the solar cell 72 alone to keep stable electric power due to the influence of the environment such as the intensity of solar radiation, but by using the power source in parallel with the battery 75, stable electric power can be supplied to the load. can do.

Inverter device 67 operating in interconnection,
68 supplies the electric power of the solar cells 73 and 74 to the interconnection system, and the electric power is output by the capacity of the solar cells 73 and 74, respectively.

Here, the inverter device 6 which is interconnected
Regarding 7, 68, the solar cells 72, 73 are not collectively arranged in parallel. Inverter device 6 for solar cells 72, 73
By dividing into 7, 68, each solar cell 7
There is an advantage that the power generation capacities of 2, 73 can be individually drawn out.

For example, when the installation environments such as the azimuth angles of the solar cells 72, 73 are different, the respective solar cells 72, 73
The optimum operating voltage of 73 may be different as shown in FIG. When the solar cells having different optimum values are collectively operated in parallel, the operating voltages of the both are made to coincide with each other, so that both or one of the operating points of the solar cells 72, 73 is
It will deviate from the optimum point.

In the case of a power generation system using a solar cell, a method of controlling the solar cell by dividing the solar cell as much as possible can be considered, and this embodiment is one of the means for realizing this.

[0207] As another example, the inverter device 6
In the case where the inverters 6 and 67 are operated independently and the inverter device 68 is interconnected, the switches 76 and 77 are turned on and the switch 78 is disconnected.

At this time, the DC power source of the inverter device 68 becomes the solar cell 74 connected to the inverter device 68, and the interconnection operation is performed.

Further, the DC power source 1 of the inverter devices 66 and 67 is turned on by turning on the switches 76 and 77.
2, 73 and the battery 75 are connected in parallel.

When the self-sustained operation load of the inverter devices 66, 67 for self-sustaining operation exceeds the total power generation capacity of the solar cells 72, 73, the excess power is supplied from the battery 75.

[0211] It is difficult to keep stable electric power only with the solar cells 72 and 73 due to the influence of the environment such as the intensity of solar radiation, but by using a parallel power supply with the battery 75, stable electric power to the load can be obtained. You can supply.

Inverter device 67 operating in interconnection,
68 supplies the electric power of the solar cells 73 and 74 to the interconnection system, and the electric power is output by the capacity of the solar cells 73 and 74, respectively.

As described above, the capacity of the solar cell can be optimally extracted as much as possible during the interconnection operation, and stable power can be supplied to the load during the self-sustaining operation.

As described above, in the inverter device of the present embodiment, the solar cells 72-74 corresponding to the number of a plurality of inverters in the inverter devices 66-68 on the DC side.
One constant-voltage DC power supply 75 is input, each DC side of the inverters that are interconnected is connected to individual solar cells 72-74, and the DC side of the inverters that operate independently is collectively operated by the solar cells 72-74. Since it is connected to the constant-voltage DC power source 74, it is possible to drive a self-sustaining load different from the electric system of the interconnection system, or to reduce the starting current of the motor load during self-sustaining operation, and it is possible to reduce In addition to individually stopping the motor load, it is possible to maximize the power generation capacity of the solar cell during interconnection, and it is possible to stabilize the DC power supply during independent operation.

(Tenth Embodiment) This embodiment can be applied to any of the third and fourth embodiments, but here, FIG.
The case of application to the fourth embodiment will be described.

FIG. 15 is a block diagram showing a configuration example of the inverter device according to the present embodiment. The same parts as those in FIG. 7 are designated by the same reference numerals, and the description thereof will be omitted. Only different parts will be described here. .

The output reference generators 24 to 26 have the same structure as that shown in FIG.
2 has the same structure as that shown in FIG.

That is, in the inverter device of this embodiment, as shown in FIG. 15, the AC side (output side) of the inverter is branched into two circuits, and one branch circuit is provided with the interconnection switch 33. And a load such as a motor is connected to the other branch circuit.

The load device has a switch that also serves as a load-specific operation switch, and the self-sustained operation switch 57 works in conjunction with the load switch.

On the other hand, the ramp generator 58 is 1 when the output signal from the self-sustained operation switch 57 is off, and is once 0 when the output signal from the self-sustained operation switch 57 is turned on, and takes a predetermined time. Increasing linearly from 0 to 1,
During the subsequent operation, outputting a ramp signal holding 1 is the same as in the case of FIG.

In FIG. 15, the ramp generator 58 further outputs a state signal 1 indicating whether the ramp signal is changing from 0 to 1 or has finished changing, and generates a sine wave for this state signal. Inputting to the device 42.

Further, the ramp generator 58 has a period during which the ramp signal is changing from 0 to 1 and a period obtained by adding a fixed time from the end of the change, as signals different from the changing signal of the state signal 1. , The state signal 2 is output as a changing signal, and this output signal is input to the operation mode setter 41.

The operation mode setter 41 is the ramp generator 5
When the status signal from 8 indicates that the ramp signal is changing, the self-sustained operation mode signal is output, and when the status signal indicates the end of change, the interconnection operation mode signal is output.

The status signal from the ramp generator 33 is transmitted to the interconnection switch 33, and when the status signal is changing, the interconnection switch 33 is opened.

Further, the sine wave generator 42 receives two kinds of signals, a ramp signal from an external ramp generator 58 and a status signal 1.

On the other hand, the sine wave generator 42 is constructed as shown in the block diagram of FIG.

That is, the present sine wave generator 42 is similar to that shown in FIG.
6, the synchronization circuit 46 and the sine wave generator 60
And a rated frequency setter 61 and a multiplier 62.

The frequency of the sine wave generator 60 can be set from the outside, and the frequency of the output signal increases in proportion to the signal.

The rated frequency setting device 61 sets a signal having a fixed value corresponding to the rated frequency.

The multiplier 62 multiplies the output signal from the rated frequency setting unit 61 and the ramp signal from the ramp generator 58, and outputs a frequency signal.

The output signal from the multiplier 62 becomes an input signal to the sine wave generator 60, and the sine wave generator 60 outputs a sine wave having a frequency according to this input signal.

The status signal 1 from the ramp generator 58, the output signal from the system voltage detector 45, and the output signal from the multiplier 62 are input to the synchronizing circuit 46.

If the status signal 1 is not a signal indicating that the state signal 1 is changing, the synchronizing circuit 46 generates a synchronizing signal based on the output signal from the system voltage detector 45, indicating that the state signal 1 is changing. In the case of a signal, a synchronizing signal is generated based on the frequency signal from the multiplier 62 and output to the sine wave generator 60, respectively.

Next, the operation of the inverter device of the present embodiment configured as described above will be described.

During the interconnection operation, the ramp signal from the ramp generator 58 is 1, and the status signals 1 and 2 indicate the end of change.

As a result, the operation mode setting device 41 outputs the signal of the interconnection mode, and the interconnection switch 33 is turned on.

In this state, since the voltage of the grid 3 is applied to the branch point on the output side of the inverter, the grid voltage is generated as it is in the load and the operation of the load can be continued.

Also, the output signal of the sine wave generator 42 is
Since the sine wave signal is synchronized based on the output signal from the system voltage detector 45, the output current of the inverter is also the sine wave current synchronized with the system 3.

On the other hand, when the switch of the load device is turned off,
The interlocking independent operation switch 57 is also turned off, but the operation of the inverter does not change, the interconnection operation is continued, and the load is only stopped.

When the switch of the load device is turned on,
The interlocking self-sustained operation switch 57 is also turned on, and the ramp generator 58 temporarily sets the ramp signal to 0, and at the same time, the status signal 1 and the status signal 2 become signals indicating that the lamp is changing.

As a result, the operation mode setter 41 outputs the signal of the self-sustained operation mode, and the interconnection switch 33 is disconnected.

The inverter temporarily stops the interconnection operation, starts the independent operation separated from the system 3, and starts the ramp generator 5
As the ramp signal from 8 increases linearly,
Gradually increase the output voltage and frequency.

As a result, a voltage is gradually applied to the load connected to the self-sustained operation output, so that the load current also gradually increases.

Immediately after the ramp signal from the ramp generator 58 reaches 1, the state signal 2 becomes a signal indicating the end of change, but the state signal 1 becomes a signal indicating that the change is in progress.

At this time, the operation mode setting device 41 outputs the signal in the self-sustaining mode, and the interconnection switch 33 remains disconnected.

On the other hand, the synchronizing circuit 46 in the sine wave generator 42 is synchronized on the basis of the voltage of the grid 3. After the ramp signal of the ramp generator 58 reaches 1, a certain period of time has elapsed and then the state signal 2 becomes a signal indicating the end of the change. Then, from this time, the operation mode setting device 41 outputs the signal of the interconnection mode, and the interconnection switch 33 is turned on, so that the inverter is switched to the interconnection operation.

Further, the system voltage is generated in the load as it is, and the operation of the load can be continued.

It should be noted that the status signal 1 from the ramp generator 58
The fixed time from the end of the change to the end of the change of the state signal 2 is the time provided until the synchronization with the system 3 is completed. This is because if the interconnection switch 33 is turned on before the synchronization is completed, a transient overcurrent may occur.

When a motor load or the like is directly connected to the system 3 for starting, an excessive current may flow at the time of starting, causing a temporary voltage drop in the system 3,
In this respect, in the present embodiment, the self-sustained operation of the inverter is used only at the time of starting, and since the load current is connected to the voltage of the grid 3 after stabilizing, it is possible to prevent the voltage fluctuation of the grid 3 at the start of the load. it can.

As described above, in the inverter device of this embodiment, when the load operation is started, the interconnection switch 3 is disconnected and the self-sustained operation is started to gradually apply the voltage to the load so that the output voltage is After reaching the voltage value, after synchronizing with the system voltage, the interconnecting switch 3 is turned on and switching to the interconnected operation that controls the output current is performed, so the starting current of the motor load is reduced during self-sustaining operation. In addition to this, it becomes possible to shift the inverter to the interconnection operation while the motor load is operating.

(Eleventh Embodiment) This embodiment can be applied to any of the fifth and sixth embodiments, but here, FIG.
The case of application to the sixth embodiment of No. 0 will be described.

FIG. 17 is a block diagram showing a configuration example of the inverter device according to the present embodiment. The same parts as those in FIG. 10 are designated by the same reference numerals and the description thereof will be omitted. Only different parts will be described here. .

That is, as shown in FIG. 17, the inverter device of this embodiment has at least one unit (two units in this example) having the same configuration as that of the inverter device of the sixth embodiment shown in FIG. Inverter devices 66 and 67, and one or more (in this example, one) general inverter device 68 that outputs a predetermined constant voltage during self-sustaining operation in addition to the interconnected operation.

The interconnection output parts of the respective inverter devices 66 to 68 are connected to the common system 3 via the manual interconnection switch 33.

Further, the self-sustained output sections of the respective inverter devices 66 to 68 can be connected to individual loads.

When the inverter device 66 or 67 is operated independently, the inverter device 66 or 67 is operated independently.
The interconnection switch 33 of No. 2 and the interconnection switch 33 of the inverter device 68 are manually disconnected.

The inverter devices 66 to 68 are constructed so as to be able to output self-sustained operation when the interconnection switch 33 in each inverter device is disconnected.

Here, the self-sustaining switch 34 of the inverter devices 66 to 67 has an operation coil 63 and can be electrically opened and closed, and only when a voltage is applied to the operation coil 63, the self-sustaining switch 34 is provided. Is supposed to be turned on.

Each of the inverter devices 66, 67 is provided with a three-pole self-sustained operation switch 57 so that the self-sustained operation can be started when each self-sustained operation switch 57 is turned on.

On the other hand, the signal of the first pole becomes the input of the operation mode setter 41 in each of the inverter devices 66 and 67, and becomes the independent operation signal for controlling each part of the inverter devices 66 and 67.

The signal of the second pole is given to the inverter device 68 and becomes the self-sustained operation start signal of the inverter device 68.

Further, the third pole is the inverter device 6
It is used as a power supply switch to the operation coil 63 in 6, 67.

Furthermore, the inverter device 68 is provided with another independent operation switch 57.

The self-sustained operation of the inverter device 68 is configured to interlock with the self-sustained operation switch 57 of the inverter devices 66 and 67.

That is, the inverter device 66 or 67
When either of the self-sustained operation switches 57 is turned on, the inverter device 68 stops the interconnection operation, starts the self-sustained operation, and promptly outputs the constant voltage.

Even when the self-sustained operation switch 57 of the inverter device 68 is turned on, the interconnection operation is stopped, the self-sustained operation is started, and the constant voltage is promptly output.

On the other hand, the constant voltage which is the output of the inverter device 68 is used as the power source of the operation coil 63 of the self-sustained switch 34 of the inverter devices 66 and 67.

Further, between the operation coil 63 of the inverter devices 66 and 67 and the output circuit of the inverter device 68 serving as a driving power source, the third pole of the self-sustained operation switch 57 of each of the inverter devices 66 and 67, A switch interlocking with each interconnection switch 33 is inserted.

The switch interlocking with the interconnection switch 33 is a switch that is closed when the interconnection switch 33 is off.

Next, the operation of the inverter device of the present embodiment configured as described above will be described.

When the inverter device 66 or 67 is operated independently, the inverter device 66 or 67 and the interconnecting switch 33 of the inverter device 68 which are operated independently are disconnected.

As a result, the inverter device 66 or 6
Among the components of the circuit that supplies the driving power to the operation coil 63 of the independent switch 34 of No. 7, the switch interlocking with the interconnection switch 33 is turned on.

When the self-sustained operation switch 57 of the inverter device 66 or 67 for self-sustaining operation among the inverter devices 66 or 67 is turned on, the signal from the second pole of the self-sustained operation switch 57 causes the inverter device 68 to operate as necessary. Independent operation is started and a constant voltage is output. at the same time,
The inverter device 66 or 67 starts an independent operation.

The output voltage of the inverter device 68 is connected to the operating coil 63 through the switch operating in conjunction with the third pole of the self-sustained operation switch 57 and the interconnection switch 33 in the device of the inverter device 66 or 67. Therefore, the self-sustained operation output of the inverter device 66 or 67 is supplied to the load via the self-sustaining switch 34.

Generally, a constant voltage is required for the coil drive voltage of a switch that electrically opens and closes, but the output of the inverter device 66 or 67 may be gradually increased from the constant voltage. Cannot be used for.

In this respect, in the present embodiment, the self-sustaining switch 34 of the inverter device 66 or 67 does not directly use the output of the inverter device 66 or 67 as a driving power source, but uses the constant voltage supplied from the inverter device 68. Therefore, even if the output voltage of the self-sustained operation of the inverter device 66 or 67 is gradually increased, power can be supplied to the load from the low voltage range.

On the other hand, when the self-sustained operation switch 57 of the respective inverter device 66 or 67 is not turned on, the inverter device 68 interlocks with the self-sustained operation switch 57 in the inverter device 68 to start or stop the self-sustaining operation, thereby making the self-sustained operation independent. Power can be supplied to the load from the operation output.

As described above, in the inverter device of this embodiment, the self-sustaining switch 34 of the branch circuit that outputs the self-sustaining output of the inverter device is used as an electrical switch, and its drive power is set to a predetermined level during self-sustaining operation. Since it is obtained from the output of the inverter device that outputs voltage, it can drive a self-sustaining load that is different from the electrical system of the interconnection system, or it can reduce the starting current of the motor load during self-sustaining operation. The self-sustained operation output in the device can be used as the drive power source for the self-sustained opening / closing device, and the power supply device for driving the opening / closing device can be omitted.

[0279]

As described above, according to the inverter device of the present invention, it is possible to operate in an interconnected manner with the grid, and in the case of independent operation separated from the grid, the voltage of the interconnected grid and It is possible to operate a load that inputs electric power different from that of the electric system without using a transformer, or it is possible to start a load that requires a starting current.

[Brief description of drawings]

FIG. 1 is a block diagram showing a first embodiment of an inverter device according to the present invention.

FIG. 2 is a block diagram showing a configuration example of an output reference generator 25 in the inverter device of the first embodiment.

FIG. 3 is a block diagram showing a configuration example of output reference generators 24 and 26 in the inverter device of the first embodiment.

FIG. 4 is a block diagram showing a configuration example of output reference generators 24-26 according to a second embodiment of the present invention.

FIG. 5 is a block diagram showing a third embodiment of an inverter device according to the present invention.

FIG. 6 is a block diagram showing a configuration example of output reference generators 24 to 26 in the inverter device according to the third embodiment.

FIG. 7 is a block diagram showing a fourth embodiment of an inverter device according to the present invention.

FIG. 8 is a block diagram showing a configuration example of a sine wave generator 42 in the inverter device according to the fourth embodiment.

FIG. 9 is a block diagram showing a fifth embodiment of an inverter device according to the present invention.

FIG. 10 is a block diagram showing a sixth embodiment of an inverter device according to the present invention.

FIG. 11 is a block diagram showing a seventh embodiment of an inverter device according to the present invention.

FIG. 12 is a block diagram showing an eighth embodiment of an inverter device according to the present invention.

FIG. 13 is a block diagram showing a ninth embodiment of an inverter device according to the present invention.

FIG. 14 is a characteristic diagram for explaining the operation of the inverter device according to the ninth embodiment.

FIG. 15 is a block diagram showing a tenth embodiment of an inverter device according to the present invention.

FIG. 16 is a block diagram showing a configuration example of a sine wave generator 42 in the inverter device of the tenth embodiment.

FIG. 17 is a block diagram showing an eleventh embodiment of an inverter device according to the present invention.

FIG. 18 is a block diagram showing a typical configuration example of a conventional inverter device.

FIG. 19 is a block diagram showing a configuration example of output reference generators 24 to 26 in a conventional inverter device.

FIG. 20 is a block diagram showing a configuration example of PWM modulators 30 to 32 in a conventional inverter device.

[Explanation of symbols]

1 ... DC power supply, 2 ... inverter bridge, 3 ... grid, 4
~ 6 ... half bridge circuit, 7 ~ 12 ... switch, 13
~ 15 ... reactor, 16 ~ 18 ... current detector, 19,
20 ... Capacitor, 21-23 ... Capacitor, 24-2
6 ... Output reference generator, 27-29 ... Current controller, 30-
32 ... PWM modulator, 33 ... Interconnection switch, 34 ... Independent switch, 35-37 ... Voltage detector, 38-40 ... Voltage controller, 41 ... Operation mode setting device, 42 ... Sine wave generator, 43, 44 ... Phase shifter, 45 ... System voltage detector, 46 ... Synchronous circuit, 47 ... Interconnection amplitude setter, 48 ...
Independent amplitude setting device, 49 ... Selector, 60 ... Multiplier, 51
... Selector, 52 ... Modulator, 53 ... Drive circuit, 54 ... Phase shifter, 55 ... Selector, 56 ... 100V setting device, 57
... Self-supporting switch, 58 ... Ramp generator, 59 ... Multiplier, 60 ... Sine wave generator, 61 ... Rated frequency setter, 6
2 ... Multiplier, 63 ... Operation coil, 64 ... Drive circuit, 65
... Auxiliary contact, 66 to 68 ... Inverter device, 69 to 71
... Auxiliary contacts, 72-74 ... Solar cells, 75 ... Batteries, 76-78 ... Switches.

Claims (7)

(57) [Claims] 1. A DC power is converted into an AC power and connected to a grid.
It has an inverter that can output the
Connected operation and independent operation separated from the above system
In the replaceable inverter device, the AC side of the inverter is branched into a plurality of circuits, and one branch circuit of the plurality of branch circuits can be connected to the system as a connection output unit, and the connection output unit A switchgear is provided between the switch and the grid power receiving point, and other branch circuits of the plurality of branch circuits can be connected to a load via the switchgear as independent output sections, and the grid output section and the grid power receiving point An inverter device, characterized in that when the switchgear provided between the two is closed, the switchgear of the self-sustained output unit is blocked. 2. DC power is converted into AC power and connected to the grid.
It has an inverter that can output the
Connected operation and independent operation separated from the above system
In the replaceable inverter device, the AC side of the inverter is branched into a plurality of circuits, and a switchgear is provided in each of the plurality of branch circuits, and one branch circuit of the plurality of branch circuits is connected to an interconnection output unit. As a result, it is possible to connect to the system via the switchgear, and to connect the other branch circuit of the plurality of branch circuits to the load via the switchgear as an independent output section, and to turn on the switchgear of the interconnection output section. The inverter device is characterized in that the switchgear of the self-sustained output unit is prevented from being turned on when the system is interconnected with the grid. 3. An inverter device configured by using a plurality of the inverter devices according to claim 1, wherein the interconnection output units of the respective inverter device bodies can be collectively connected to the same system. The switchgear on the side is provided between the collective point and the power receiving point, and when the switchgear is turned on, the switchgear of the independent output units of all the inverters is blocked from being turned on. And inverter device. 4. An inverter device configured by using a plurality of the inverter devices according to claim 1 or 2, wherein the interconnection output parts of the respective inverter device bodies can be connected to the same system, An inverter device characterized in that, when the one or more inverters are separated from the system for independent operation, a command to start operation of the inverters that perform the independent operation is individually given. 5. The inverter device according to claim 3 or 4, wherein a solar cell power source and one constant voltage DC power source corresponding to the number of a plurality of inverters in the inverter device body are provided on the DC side. Input, each DC side of the inverter that operates in conjunction with the grid is connected to an individual solar cell power supply, and the DC side of the inverter that operates independently by disconnecting from the grid is the solar cell power supply and constant voltage collectively. An inverter device characterized by being connected to the DC power supply of. 6. An inverter capable of converting DC power of a DC power supply into AC power and outputting the AC power by linking to the grid, means for controlling an output current of the inverter to a desired value, and an output voltage of the inverter. And a means for controlling to a desired value, when operating the inverter in conjunction with the grid, when controlling the output current of the inverter to a desired value, when operating the inverter independently from the grid In an inverter device in which the output voltage of the inverter is controlled to a desired value and the output voltage at the start of operation is gradually increased to a predetermined value, the AC side of the inverter is branched into two circuits. When one of the branch circuits is provided with a switchgear and is connected to a system, the other branch circuit is connected to a load, and when the load is started, the switchgear is disconnected. Both start self-sustaining operation that is not connected to the grid, gradually apply voltage to the load, synchronize with the grid voltage after the output voltage reaches the voltage value of the grid, and then turn on the switchgear and output current. An inverter device characterized by being switched to an interconnected operation for controlling the. 7. One or more inverter devices according to claim 1 or 2, and one or more inverter devices that output a predetermined constant voltage when operating independently without being connected to a grid. In an inverter device configured by using, a switch device of a branch circuit that outputs a self-sustaining output of the inverter device main body according to claim 1 or 2 is a device that electrically opens and closes, and the drive device of the switch device. An inverter device characterized in that electric power is obtained from an output of an inverter device body that outputs a predetermined constant voltage when performing the self-sustaining operation.