JPH07222456A - Inverter system - Google Patents

Abstract

PURPOSE:To provide a system which facilitates the improvement of the utilization of the installation space, wiring equipment, etc., while inverters can be applied to general purposes and, further, which is excellent in respect of function and maintenance. CONSTITUTION:A converter unit 1 and a dynamic brake unit 2 are provided in common. A number of inverter units 111-1N are composed of main circuits 11A and controllers 11B which have minimum necessary circuits for the control and protection of the main circuits 11A. Various types of monitoring, controlling and setting functions and a control power supply are provided in a master controller 13 and the signal transmission and the control power supply distribution between the master controller 13 and the respective inverter modules are realized by bus connections composed of bus-bars 13A.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an inverter system for driving a large number of AC motors with a large number of inverters.

[0002]

2. Description of the Related Art Large-scale machinery such as textile machines, printing machines, and textile machines are equipped with a large number of induction motors and synchronous motors, and inverters for operating these motors collectively.
The system is prepared.

As a conventional inverter system of this type, there is a method of installing a required number of general-purpose inverters, or a method of installing a required number of inverter sections by sharing a converter section.

FIG. 13 shows a case where the converter section is shared. The shared converter unit 1 converts AC power from the AC power supply AC into DC power. This converter unit 1
Rectifier (or forward converter with DC voltage control function) 1A
And a pre-charging circuit 1B and a smoothing capacitor 1C.

A dynamic brake (dynamic braking) section 2 commonly used with the converter section 1 is provided with a transistor 2A as a switch element and a resistor 2B, and when a DC overvoltage is about to be generated by regenerative power from the inverter side. Then, it is absorbed by the resistor 2A when the transistor 2A is turned on.

In the N inverter units 3 _{1 to} 3 _N , the converter unit 1 and the dynamic brake unit 2 are used as a common DC power source, and the switch elements (semiconductor elements such as IGBT, power transistor, GTO) of the main circuit are turned on. .One or a plurality of AC motors 4 that become loads by OFF control
Supply AC power with voltage and frequency control to ₁ to 4 _N.

The control of each of the inverter units 3 _{1 to} 3 _N is individually controlled by external controllers 5 _{1 to} 5 _N (which may be incorporated in the inverter unit). Of these, the controller 5 ₁ is also provided with a control function for the converter unit 1 and the dynamic brake unit 2. Further, the converter unit 1, the dynamic brake unit 2, and the inverter unit 3 ₁
Also, the controller 5 ₁ may be one inverter.

The user controller 6 sets the operation / stop of each of the inverters 3 _{1 to} 3 _N , the output frequency, etc., and these various commands and data are sent to the controllers 5 ₁ to 5.
Give to 5 _N.

The controllers 5 _{1 to} 5 _N exemplify the control part configuration of the inverter section in FIG. The step input selected by the input selector 7 ₁ is converted by the cushion circuit 7 ₂ into an input signal having a constant gradual slope, and the frequency jump circuit 7 ₃ responds to this input signal to prevent mechanical system resonance. The input current is converted into an input signal that avoids the frequency range set for
₄ according to the voltage and frequency generator 7 ₅ based on the overcurrent limiting V
A voltage control signal V and a frequency control signal F having a constant / F ratio are obtained, and a main circuit control signal for the inverter section is obtained in a PWM (pulse width modulation) circuit 7 ₆ .

Further, a sequence circuit 7 for stopping the operation of the inverter unit and other control according to a command from the outside.
_7, a protection circuit 7 ₈ for the protection of the inverter unit also comprises various signal input circuit for these control and protection.

[0011]

In installing an inverter system, instead of providing a special space as an electric room for the purpose of space saving, maintenance, and reduction of wiring work cost, an inverter is installed in a control panel on site or There is a demand for an equipment configuration that is directly incorporated in a machine.

In response to such a demand, the conventional inverter system configuration has the following problems.

(1) The simplest system configuration is to prepare an individual inverter device for each electric motor, but since each individual inverter device has many functions as a general-purpose product, it is unnecessary as an actual facility. The configuration also includes the functional parts, and in a system using a large number of inverter devices, the equipment outline is large and the mounting space is large. Also, in terms of function, a large number of unnecessary function units are included, which reduces maintainability.

(2) In the system configuration in which the converter section is shared, the space cost of this section can be reduced,
Each of the controllers 5 _{1 to} 5 _N still needs the single control function of the inverter unit, and this functional unit is wasted.

(3) Regardless of (1) the method of individually installing the general-purpose inverter device or (2) the method of sharing the converter unit, the user controller 6 individually signals the controllers 5 _{1 to} 5 _N. Requires wiring equipment to give
Large-scale wiring equipment is required to connect the two.

(4) Since each inverter device is an individual unit, and its mounting method, direction, etc. are standardized as general-purpose products, it is often difficult to directly mount it on a machine having a complicated shape.

It is an object of the present invention to provide an inverter system which has general versatility in an inverter, enhances equipment efficiency in a mounting space and wiring equipment, and is excellent in function and maintenance.

[0018]

SUMMARY OF THE INVENTION In order to solve the above problems, the present invention provides an inverter system in which a converter is shared and a large number of loads are driven by a large number of inverter units. And a controller having a minimum control circuit necessary to control and protect the switching elements thereof, and an inverter module configuration, and a master controller that is bus-coupled to each of the inverter modules and the converter. The controller is a functional circuit for controlling the accessory of each inverter section, a start / stop control circuit, a monitoring / control / setting circuit common to each inverter section, and a common control power supply for distributing control power to each inverter, A control circuit for the converter, and the bus for each inverter unit and converter. Through wherein a structure for transmission and distributed.

Further, the present invention is characterized in that the converter has a structure in which the regenerative energy from the load side is absorbed by the dynamic brake unit, or a bidirectional conversion circuit structure in which the regenerative energy is regenerated to the AC power supply side.

Further, according to the present invention, the control power supply from the master controller to each inverter unit is supplied as low-voltage DC through the bus to perform DC-DC conversion in each inverter unit, or the bus. It is characterized in that it is supplied as an alternating current through the converter and is subjected to AC-DC conversion with the transformer in each inverter section.

Also, in the present invention, the inverter module has a coupling structure in which the main circuit and a controller board are stacked, and the master controller and each inverter unit are coupled by connecting the bus to each inverter unit. The feature is that the wiring is provided across the controller.

[0022]

[Operation] The controller is an inverter module that is the minimum required configuration for controlling and protecting the main circuit.
By providing the master controller with the control / setting function and the control power supply, the inverter module itself has the same configuration even when the machine system to which the inverter system is applied is changed, and the change on the master controller side is sufficient. It enhances versatility and facilitates function changes and maintenance.

By mounting the master controller and each inverter module with a bus for wiring, and by modularizing the inverter, the mounting space and wiring facility efficiency are increased.

A dynamic brake or a bidirectional conversion circuit is used for the regeneration of the converter section, and the control power distribution to each inverter module is set to direct current or alternating current, thereby facilitating the expansion of the functional aspect.

[0025]

FIG. 1 is a block diagram showing an embodiment of the present invention, in which the same functional portions as those in FIG. 13 are designated by the same reference numerals. The converter unit 1 and the dynamic brake unit 2 are shared as in the conventional case.

The inverter modules 11 _{1 to} 11 _N are
Inverter main circuit 11A and controller 11B, respectively
Comprising a, the power is connected to the converter section 1 and the dynamic brake portion 2 of the common, one or a plurality of motors 4 ₁
Supply controlled AC power to 4 _N.

Here, the inverter main circuit 11A is equivalent to one of the conventional inverter units 3 _{1 to} 3 _N. The controller 11B mounts a minimum required function as an independent inverter, eliminates unnecessary function mounting, and has a compact and low-cost configuration.

FIG. 2 shows a configuration example of the controller 11B. PWM circuit 12 ₁ generates a PWM signal by receiving a frequency command F and the voltage command V, to drive the main switching elements of the inverter main circuit 11A.

The voltage / frequency generator 12 ₂ gives the input frequency signal F as it is to the PWM circuit 12 ₁ as the frequency command F, and obtains the output voltage V by the following calculation to obtain P
It is given to the WM circuit 12 ₁ .

[0030]

[Formula 1] V = K _VF × F + K _VB (F _TR0 −F) K _VF : Proportional coefficient of voltage V and frequency F K _VB : Boost coefficient F _TR0 : Base frequency These coefficients and constants are IC bus interface 12
Give from outside through ₃ . Further, when the required output voltage characteristic is not obtained even by the calculation of the output voltage V by the voltage / frequency generator 12 ₂ , the changeover switch 12 ₄
Is externally applied through the IC bus interface 12 ₃ .

The reason why the voltage must be set from the outside will be described. In a normal induction motor, as shown by the solid line in FIG. 3A, the V / F ratio is made constant according to the rating of the motor. However, inverter drive motor V / F ratio varying complexity to be a polygonal line or a curve as shown by the broken line is required in the permanent magnet motor or the like, in the case of obtaining the characteristic in place of the voltage-frequency generator 12 ₂ It is given as voltage data from the outside.

Further, the permanent magnet motor, as shown in FIG. 3 (b), until entering the synchronization at the time of start-up, is driven with a low frequency (0.5~1H _Z), the output voltage V This Get up synchronously while avoiding overcurrent by starting at a slower slope. In such a case as well, independent control of the voltage V and the frequency F is required, and the external setting is performed instead of the calculation of the voltage / frequency generator 12 ₂ .

In this way, the required voltage V and frequency F characteristics vary depending on the characteristics of the motor that serves as the load of the inverter unit, so that the voltage that is used each time the motor serving as the load is replaced with a new one or for maintenance. · operation parameters of the frequency generator 12 ₂ eliminates complicated to change in accordance with the electric motor, to facilitate changes in the system by performing a change by an external setting, increasing the versatility.

[0034] Returning to FIG. 2, the overcurrent limiting circuit 12 _5,
In addition to obtain a frequency F that overcurrent limiting with respect to the frequency F ₀ which is set from the outside through IC bus interface 12 _3, in case the output frequency decreases due to an overload is not preferable for mechanical devices, the frequency F ₀ A bypass switch 12 ₆ that bypasses and outputs as the frequency F is provided.

The reason for bypassing the frequency by the bypass switch 12 ₆ will be described. Normally, in the inverter drive, a stall prevention function of lowering the output frequency and the voltage and maintaining the output torque is required so that the load of the electric motor does not become too large and exceeds the overload withstanding capacity of the inverter.

FIG. 4A shows the slip-torque-current characteristics of the induction motor. When the load increases while the output frequency remains constant, the increase in slip causes the generated torque to become AB-.
Although the torque increases in the order of C, when the peak point C is exceeded, the generated torque decreases like D and E, causing a stall phenomenon in which the speed of the electric motor decreases at once.

Therefore, in order not to exceed the peak torque (point C) and the current does not increase, the overcurrent limiting circuit 12
_{In step 5} , the output frequency is lowered as shown in FIG.

Although this overcurrent limitation is effective in preventing stalls, it causes inconvenience depending on the mechanical device.

That is, in synthetic fiber production, etc., an electric motor is used in a large number of steps from yarn production to winding, and any one of these electric motors causes a reduction in speed.
In addition, if the production progresses without recognizing the decrease in speed, low-quality products will be mixed.

Since the quality control accuracy of such mechanical equipment is required to be very high, the speed reduction of some motors due to the prevention of overcurrent is an inappropriate control. Rather, it is preferable in terms of quality control to stop production due to overcurrent failure.

In order to meet this type of requirement, therefore, a bypass switch 12 ₆ is provided in the overcurrent limiting circuit 12 ₅ so that the frequency drop due to the overcurrent prevention can be eliminated.

Returning to FIG. 2 again, the protection circuit 12 ₇ is provided in order to protect the switching element of the inverter main circuit 11A from the protection mechanism built in the output of the inverter main circuit 11A or the DC input section or the inverter switching element. Signal to block the PWM output signal. In addition to this, the temperature protection function of the switching element is also provided by the detection signal from the temperature detector 11A ₁ that detects the temperature around the switching element itself or the heat sink provided in the inverter main circuit 11A.

FIG. 5 shows an example of the protection circuit 12 ₇ . This overcurrent detection is performed by the DC current detector CT _{1 of the} inverter main circuit 11A or the output current detector CT ₂ of the inverter main circuit 11A. For detection by the output current detector CT ₂ , the positive current maximum value and the negative current maximum value of each phase (R, S, T) or two phases are divided and taken out from the separation circuit SC.

The pair of comparators CMP ₁ and CMP ₂ are
Current detector CT ₁ or CT ₂ provided as either one
The presence / absence of an overcurrent is detected by comparing the detected current from V and the overcurrent comparison reference signals + V ₁ and −V ₁ .

The overcurrent detection signal of the comparator CMP ₁ or CMP ₂ is turned into a cutoff signal of the cutoff circuit of the PWM circuit 12 ₁ via the OR gates OR ₁ and OR ₂ , and at the same time, as a cutoff control notification signal, an external IC (inverter). Output to the master controller 13 side described later through the (control) bus.

For temperature protection, a temperature detector 1 such as a thermistor is used.
The output voltage of 1A ₁ is converted into a digital signal by an external analog-to-digital converter A / D, and a digital arithmetic circuit (or a software arithmetic circuit when the controller unit 11B includes a microprocessor).
Detects whether the value converted into temperature by OPE exceeds the overheat temperature, and when it exceeds, OR gate OR
Get protective action through ₂ .

The OR gate OR ₁ is the main inverter circuit 1
When 1A itself has a protection function against overcurrent, temperature, etc., the detection output from the protection function section 11A ₂ is also taken in to obtain a cutoff control signal for the cutoff circuit.

[0048] Returning back to FIG. 2, the control power supply 12 ₈ distributed supplies to each unit in the controller 11B receives power supply for power source and the switching element drive control circuit from the outside of the IC bus.

The transmission of the various signals through the power supply system and the aforementioned IC bus interface 12 ₃ is in the configuration shown in FIG.

In FIG. 6, the control power supply is such that a low voltage power supply circuit for the controller 11B is provided in the switching or analog constant voltage control power supply 13 ₁ of the master controller 13, and this power supply line is part of the IC bus 13A. It is supplied to the controller unit 11B through the line.

In the controller section 11B, the IC bus 13A
The control power supply ₁ is loaded from the power supply line of
2 ₈ and the PWM circuit 12 ₁ are distributed to the base drive power source and the like required.

Various signals transmitted by the IC bus 13A are serial transmission buses (eg RS422, RS422,
Transmission / reception circuit 13 ₂ as a bus according to the RS485 standard,
11B ₂ transmits and receives. Further, one sequence control signal line EMS for emergency stop is provided.

Next, the master controller 13 operates as shown in FIG.
The inverter module 11 ₁ to _{1 having the} configuration shown in FIG.
1 _N (see FIG. 1) and its peripherals (converter unit 1,
The dynamic brake unit 2) is controlled. Its constituent functions will be described below.

(1) Each inverter module is provided with a corresponding setting operation section 13 _2, which has a digital operation function corresponding to, for example, a cushion circuit or a frequency jump circuit included in the conventional controllers 5 _{1 to} 5 _N. It becomes unnecessary to provide a functional circuit in the controller unit 11B.

(2) A logic operation unit 13 ₃ individually corresponding to each inverter module is provided, and for example, a digital operation function equivalent to the control unit 7 ₇ provided in the conventional controllers 5 _{1 to} 5 _N is provided, and this functional circuit is provided. The controller section 11
It is not necessary to provide B.

(3) The monitoring / control / setting unit 13 _{4 of the} controller has a numerical logic operation function for linking the setting operation unit 13 ₂ and the logic operation unit 13 ₃ and various set values of each inverter / module. A setting function for transmitting (for example, V / F boost coefficient) to each inverter module,
It has a function of performing various monitoring including the master controller 13 itself and performing input / output with the man-machine interface.

(4) IC bus interface 13 ₅
Drives the IC bus 13A with the data exchanged with each inverter module and takes in a signal from each inverter module from the IC bus 13A.

(5) User interface 13
₆ receives various setting values and commands from the user controller 6, also exchanges signals for notifying the state of the machine to the user. The transmission and reception of this signal is performed by a parallel signal or a serial signal from a contact or the like.

[0059] (6) a common control power source 13 _1, the gain control power required for the controller 13 itself and the controller 11B as.

(7) The converter control unit 13 ₇ performs switch control of the pre-charging circuit of the shared converter unit 1 and the like.

(8) Dynamic brake controller 13
Reference numeral ₈ controls the transistor 2A and the like of the shared dynamic brake unit 2.

Next, the transmission signal of the IC bus 13A will be described. The IC bus 13A is the master controller 1
3 and each of the inverter modules 11 _{1 to} 11 _N and the other converter unit 1 and the like are connected to perform the following signal transmission.

(11) 1: N signal transmission is performed by a transmission line of RS422 standard or RS485 standard, and transmission by electric signal or optical signal is performed.

(12) An emergency stop sequence control line (E) directly connected to the operator to cope with a transmission error
MS).

(13) A low-voltage common control power source is distributed from the master controller 13 to each inverter module.

(14) The data flowing through the transmission line includes frequency setting, voltage setting, other control coefficient setting, gate on / off, and failure reset signal for each inverter module. Further, each inverter module has a detection value such as a frequency, an output voltage, an output current, a DC current, a protection operation result, and a gate on / off. Other signals include a DC voltage detection value, a command / detection value for the converter unit, and a command / detection value for the dynamic brake unit.

From the above, according to the present embodiment,
A required number of inverter modules 11 _{1 to} 11 _N having a minimum required control function, a converter unit 1 and a dynamic brake unit 2 that are used as a common DC power source for each inverter module, and each inverter module and converter unit. A system including a master controller 13 for monitoring / setting / controlling 1 and the like, and a control power supply required for each, an IC bus for coupling each part with a bus configuration and a serial system for sushi signal transmission, and a user controller 6. Because of the configuration, the following effects are obtained.

(1a) By modularizing each function required for the inverter, any combination can be performed, and waste of cost and space is reduced as compared with the case of combining a plurality of conventional general-purpose products.

(1b) The size of each inverter module can be reduced by simplifying its function.

(1c) The master controller, which controls the whole, facilitates connection with the user interface.

(1d) Since various settings are made by the master controller, it is not necessary to reset each inverter module even if each inverter module is replaced.

(1e) Since it is modularized, each inverter module can be arranged in either a centralized or distributed manner.

(1f) Since each module is coupled by the IC bus which becomes a common bus, necessary signals are transmitted by serial transmission, and the control power source is also supplied to the bus, wiring is reduced.

FIG. 8 is a block diagram showing another embodiment of the present invention. The figure shows the case of performing the regeneration of the respective motor ₄₁ to supply AC side by the bi-directional conversion unit 1D was replaced with absorption or rectifier 1A regenerative energy by the dynamic braking unit 2 from _N.

In the power regeneration, the bidirectional converter 1D is configured as a voltage type inverter, and rectification by a diode and regeneration by a switching element are performed. The converter control unit 15 controls the switching element for the regenerative operation. In the system configuration in which the bidirectional conversion unit 1D has the regenerative function, the dynamic brake unit 2 is not provided.

The converter control section 15 uses the IC bus 13A.
Is connected to the master controller 13 and is controlled and monitored by the master controller 13. In addition to the basic regenerative control, the converter control unit 15
It also has a function of protecting the switching element of the bidirectional converter 1D.

The regenerative control by the dynamic brake unit 2 is performed by the dynamic brake control unit 13 ₈ as in the case of FIG. 1, and the bidirectional conversion unit 1D is configured as a rectifier.

At this time, the dynamic brake control unit 13 ₈ is connected to the IC bus 13A and is monitored and controlled by the master controller 13. In addition to the basic control, the dynamic brake control unit 13 ₈
It also has the function of protecting the switching elements and resistors of the dynamic brake unit 2.

According to this embodiment, one of the dynamic brake unit 2 and the bidirectional conversion unit 1D is selected as the regeneration function on the side of the converter unit 1 that serves as a power source shared by the inverter modules, and this selection is performed. The system configuration can be selected as a module to be connected to the IC bus, and it is easy to add and change the system, and the arrangement can be freely performed.

FIG. 9 is a power supply system diagram showing another embodiment of the present invention. Master controller 13 to IC bus 13
Controller 1 of each inverter module via A
The control power supply supplied to 1B is converted into voltage-controlled AC by an AC-AC converter 13 ₉ provided in the master controller 13, as shown in FIG.

The controller 11B of each inverter module receives the AC power supplied through the IC bus 13A as a transformer input and rectifies the AC power as it is to obtain a necessary control power supply.

[0082] AC - AC converter 13 _9, in FIG. (B)
As shown in the circuit example, the AC input is smoothed by the diode D and the capacitor C and is once converted into DC, and the positive / negative is generated by the transformer Tr having the primary winding as two windings, the switching circuit SW, and the switching elements Q ₁ and Q ₂ . The pulse power with which the crest value is the same is obtained on the secondary side of the transformer Tr.

According to this embodiment, the control power is distributed to each inverter module by alternating current, and
The module has a configuration in which it is directly received by a transformer and rectified, which has the effect of simplifying the power supply circuit configuration of each inverter module and reducing the wiring.

FIG. 10 shows an embodiment of the coupling structure of the inverter modules 11 _{1 to} 11 _N and the master controller 13 by the IC bus 13A.

Each inverter module is connected to the master controller 13 by a single IC bus 13A. With this structure, the IC bus 13A has a configuration in which the signal line and the control power supply line are separated or integrated.

Each inverter module has an inverter main circuit 11A in which the input terminals P and N, the output terminals U, V and W, and various signal line / gate terminals G are exposed to the outside, and the inverter main circuit 11A is superposed and coupled. And a controller 11B having a printed circuit board structure. For this coupling, a screwing mechanism via a spacer and a terminal G are formed so as to penetrate / solder the board of the controller 11B. I
The C bus 13A is connected to the terminal of the controller 11B.

Further, the controller 11B has the same plane shape as that of the inverter main circuit 11A, and facilitates integration with the inverter main circuit 11A. Note that when the both the planar shape difficult from the density mounting of circuit components to the controller 11B, as a front view and a side view in FIG. 11, a substrate 11B ₁ to implement the control circuit portion of the controller 11B A board 11 on which a gate circuit and a control power supply are mounted
It is also possible to have a two-sheet structure with B ₂ .

According to the present embodiment, since each inverter module has the function of the controller 11B minimized, it can be directly coupled to the inverter main circuit 11A, and the wiring of the gate signal and the like can be eliminated. In addition, each inverter
Modules can be connected by the IC bus 13A having one or two modules, and wiring can be extremely reduced.

FIG. 12 shows an example of the terminal structure of the inverter main circuit 11A. In FIG. 9A, the terminals U, V, W and the terminals P, N are L-shaped, and the terminal portions are exposed on the side surfaces.

With this structure, as shown in FIG. 9B, terminals U, V and W are connected to the controller 11B in a superposed connection.
It facilitates the direct connection with the main circuit 11A and the connection using the screw 11 or the contactor 11A ₂ for the wiring connection between the main circuit 11A and the electric motor or the converter section.

Similarly, as shown in (c) of the figure, the plate terminals U, which are projected to the side of the inverter main circuit 11A,
It may be V, W, P, N. Also in this case (d)
As shown in, the connection with the controller 11B and the connection with the electric motor are facilitated.

[0092]

As described above, according to the present invention, in an inverter system in which a converter is shared and a large number of loads are driven by a large number of inverter units, each inverter unit controls the main circuit and its switching elements. In order to make the master controller have various monitoring, control and setting functions and control power supply that a conventional general-purpose inverter has, it has the following inverter module configuration with a controller that has the minimum necessary control circuit for protection. Has the effect of.

(1) The inverter module itself has the same structure for the difference in the mechanical device to which the inverter system is applied, and the change on the master controller side is sufficient.
Make it easy to design and change the system.

(2) The inverter module does not need to recognize the use of individual data, and there is no need to set data when the inverter module is damaged or replaced, thus improving maintainability.

(3) The inverter module can be reused if its capacity matches the applied mechanical device. Therefore, the versatility is improved and the spare parts are commonly used to improve maintainability.

(4) Since the inverter module has the minimum necessary configuration including the control power supply, it can be made compact.

Further, according to the present invention, the mounting space and the wiring facility efficiency can be improved by connecting the master controller and each inverter module by a bus for wiring and by modularizing the inverter.

Further, according to the present invention, the regeneration of the converter section is made to be a dynamic brake or a bidirectional conversion circuit, and the distribution of the control power supply to each inverter module is made to be direct current or alternating current. become.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing an embodiment of the present invention.

FIG. 2 is a configuration example of a controller unit 11B of the embodiment.

FIG. 3 shows an example of frequency / voltage characteristics of inverter control.

FIG. 4 is a slip-torque / current characteristic diagram of inverter control.

FIG. 5 shows an example of a protection circuit 12 _{7 according to} the embodiment.

FIG. 6 shows an example of a power supply system and a signal system of the embodiment.

FIG. 7 is a configuration example of a master controller 13 of the embodiment.

FIG. 8 is a configuration diagram of another embodiment.

FIG. 9 is a power system diagram of another embodiment.

FIG. 10 is an example of mounting by the IC bus of the embodiment.

FIG. 11 is a configuration example of an inverter module according to the embodiment.

FIG. 12 is an example of a terminal structure of the inverter section 11A of the embodiment.

FIG. 13 shows an example of a conventional system shared by converters.

FIG. 14 is a configuration example of a conventional controller.

[Explanation of symbols]

1 ... Converter part 2 ... Dynamic brake part 6 ... User controller 11 ₁ , 11 ₂ ... Inverter part 11A ... Inverter main circuit 11B ... Controller 13 ... Master controller 13A ... IC bus

Claims (4)

[Claims] 1. In an inverter system in which a converter is shared and a large number of loads are driven by a large number of inverter units, each of the inverter units is a minimum control required to control and protect a main circuit and its switching elements. An inverter module having a controller having a circuit, and a master controller bus-connected to each of the inverter modules and the converter, wherein the master controller is a functional circuit for controlling an accessory of each inverter unit. And a start / stop control circuit, a monitoring / control / setting circuit common to each inverter unit, a common control power supply that distributes control power to each inverter, and a control circuit for the converter. Inverter characterized by a structure for transmission / distribution through the bus system. 2. The configuration in which the converter absorbs regenerative energy from the load side by a dynamic brake unit,
Alternatively, the inverter system according to claim 1, wherein the inverter system has a bidirectional conversion circuit configuration in which the AC power is regenerated. 3. The control power supply from the master controller to each inverter unit is supplied as low-voltage DC through the bus and converted into DC-DC in each inverter unit, or AC through the bus. 2. The inverter system according to claim 1, wherein the inverter system is configured to be supplied as an AC power supply and converted into AC-DC with a transformer in each inverter unit. 4. The inverter module has a coupling structure in which the main circuit and a substrate of a controller are stacked, and the master controller and each inverter unit are coupled to each other,
2. The inverter system according to claim 1, wherein the bus is wired to the controller of each inverter unit.