JPH0759356A - Supplying method for control power in common control device - Google Patents

Abstract

PURPOSE:To ensure a control power supply for common control devices to comprehensively control a plurality of control devices, and reduce the size and price thereof. CONSTITUTION:Power buses of positive polarity of inverter devices 2, 3 and their respective power circuits 12, 13, are connected together in a batch on the cathode side with diodes D1, D2 connected in serial in-between, respectively. The power buses connected together in a batch form the positive control power bus to a control circuit 15. The power buses of the power circuits 12, 13 of negative polarity are directly connected together in a batch, and form the negative control power bus to the control circuit 15. The control circuit 15 is supplied with required D.C. control power through these positive and negative power buses, which makes unnecessary any power circuit dedicated thereto.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control power supply method for a common control device for comprehensively controlling a plurality of inverter devices, each of which drives a fan or an electric motor for driving a pump as its load, according to a control target such as temperature or water pressure. Regarding

[0002]

2. Description of the Related Art Conventionally, as a method of supplying a control power source as described above, a method performed according to a circuit diagram illustrated in FIG. 2 is known. FIG. 2 shows a supply path of a DC control power source to the common control circuit when the two sets of the electric pump driving inverter devices are comprehensively controlled by the one set of the common control circuit by controlling the water supply pressure and the like. .

In FIG. 2, reference numerals 2 and 3 denote inverter devices having the same structure. For example, the inverter device 2 is an inverse conversion circuit having a diode rectifying circuit, a smoothing capacitor, and a transistor having a diode antiparallel to the inverse conversion circuit. The main circuit section 8 and the control circuit section 10 having the power supply circuit 12 are used, and the electric motor 4 that drives the pump 6 is used as its load. Similarly, the inverter device 3 includes a control circuit section 11 having a main circuit section 9 and a power supply circuit 13 for the main circuit section 9.
And has the electric motor 5 that drives the pump 7 as its load.

The two inverter devices 2 and 3 share the AC power supply 1 and receive AC power for the main circuit and the control circuit. In addition, the 24 common control circuit units input the input signal S _I to the inverter devices 2 and 3
And a signal S _O1 and a signal S _O2 organized from this signal S _I , respectively, are received as common control signals for
It is output as a control signal for the signals 1 and 3, and these two devices are comprehensively controlled according to the signal S _I.

The common control circuit section 24 is composed of a control circuit 15 for performing the above-mentioned signal organization and a power supply circuit 25 composed of a transformer, a diode, a smoothing capacitor and the like. That is, as a conventional control power supply method for a common control device such as the common control circuit unit 24, the common control device has its own control power supply circuit and is controlled by the output signal of each inverter device. The dedicated control power supply circuit is configured independently of the control power supply circuit of each of the plurality of control devices.

[0006]

However, according to the conventional control power supply method as shown in the circuit diagram of FIG.
If any failure occurs in the control power supply circuit of the common control device itself, this common control device cannot operate normally,
Therefore, a system composed of control devices such as a plurality of inverter devices that are comprehensively controlled by applying the output signal of this common control device must also stop its operation, and the reliability of this system is unavoidably deteriorated. It was

Furthermore, the fact that the above-mentioned common control device has its own control power supply circuit has led to its large size and high price. In view of the above, the present invention relates to the common control device that enables improvement of the reliability of a system including a plurality of control devices that are comprehensively controlled by the common control device and reduction in size and cost of the common control device. The purpose is to provide a method of supplying control power.

[0008]

In order to achieve the above object, a control power supply method for a common control device according to the present invention comprehensively controls a plurality of inverter devices which are operated with respective loads such as electric motors. A control power supply method for a set of common control devices, wherein the common control device is provided with a priority circuit for selecting the control power supply, and one of the control power supplies in the control circuit unit of each of the inverter devices is prioritized. It is selected through a circuit and used as a control power source for the common control device.

[0009]

In a system composed of a common control device and a plurality of control devices which are comprehensively controlled by the output signals thereof, for example, a plurality of inverter devices each having an electric motor as a load, each of the plurality of control devices usually has its own control power source. Is to have. Therefore, regarding the control power supply in the system, the control voltage is unified and the control power supply capacity is coordinated so that the control power required for the common control device can be supplied from any of the control power supplies of the plurality of control devices. In addition, if the supply from the control power supply of any one of the control devices is selected, the common control device does not need to have its own control power supply.

In accordance with the above, the present invention relates to a control power supply for a common control device for comprehensively controlling a plurality of control devices. The common control device is provided with a priority circuit for selecting the control power supply, and the common control device is provided via this priority circuit. The control power required for the control power supply is set so that it can be supplied from any of the control power supplies of the plurality of control devices, and the supply of the control power from the control power supply of any one of the control devices is selected.

Here, when the control power supply of each of the devices is a direct current, the priority circuit has a diode OR connection in which each positive or negative power supply bus in each of the direct current control power supplies is used as its input bus. It is configured, for example, positive power source bus in each DC control power source is collectively connected via a diode connected in series, respectively, positive control power source bus in the common control device with this collective connection side In addition, the negative power source buses of the respective DC control power sources are directly connected together to form the negative control power source buses of the common control device.

According to the priority circuit configuration as described above, the control power source having the maximum DC voltage is automatically selected and connected to the common control device. Therefore, even if a voltage drop accident occurs in any of the control power supplies, the common control device can secure its DC control voltage and retain its control function without having its own control power supply. Becomes

Further, when the control power of the common control device is obtained from the AC side of each control device control power supply, the priority circuit for selecting the control power supply is a combination of an AC low voltage relay and a circuit switching relay. The control power is supplied from each device control power supply whose AC voltage is normal, and the common control device can retain its control function.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention will be described below with reference to the circuit diagram of FIG. In FIG. 1, constituent elements having the same functions as those in the embodiment of the prior art shown in FIG. 2 are designated by the same reference numerals. FIG. 1 shows a modification of the common control circuit section 24 in the circuit diagram of FIG. 2 to form a common control circuit section 14. The DC control power supply system of each control device is shown as in the case of FIG. It is a thing.

FIG. 1 shows a power supply circuit 12 of the inverter device 2.
And the power supply circuit 13 of the inverter device 3 are collectively connected on the cathode side through the diodes D ₁ and D ₂ that are connected in series to each other and connected to the control circuit 15 through the collective connection side. The figure shows a state in which the control power supply bus of positive polarity is not formed, and the power supply buses of negative polarity in both the power supply circuits 12 and 13 are directly and collectively connected to form a negative control power supply bus for the control circuit 15. .

That is, FIG. 1 shows the common control circuit section 2 shown in FIG.
4, a dedicated power supply circuit 25 for the control circuit 15
This is a state in which the required DC control power is supplied from both the positive and negative control power supply busbars formed as described above by removing it, and the dedicated power supply circuit for the control circuit 15 is no longer required.

[0017]

According to the present invention, there is provided a control power supply method for a common control device for comprehensively controlling a control device such as a plurality of inverter devices each having a load such as a fan or an electric motor for driving a pump. By providing a priority circuit for selecting the control power source and selecting one of the control power sources in the control circuit units of the plurality of control devices as the control power source of the common control device via the priority circuit, When a voltage drop accident occurs in any of the control power supplies of each control device, the common control device secures its control voltage and retains its control function without having its own control power supply. As described above, it is possible to continue the operation of the system including a plurality of control devices and improve the reliability of system operation.

Further, since the dedicated control power supply circuit is not required for the common control device, the size and cost can be reduced.

[Brief description of drawings]

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

FIG. 2 is a circuit diagram showing an example of a conventional technique.

[Explanation of symbols]

 1 AC power supply 2 Inverter device 3 Inverter device 4 Electric motor 5 Electric motor 6 Pump 7 Pump 8 Main circuit part 9 Main circuit part 10 Control circuit part 11 Control circuit part 12 Power circuit 13 Power circuit 14 Common control circuit part 15 Control circuit 24 Common control Circuit 25 power supply circuit

Claims (1)

[Claims] 1. A method for supplying control power to a set of common control devices for comprehensively controlling a plurality of inverter devices each of which is operated with a load such as an electric motor, wherein the common control device has its control power supply. A common control device, wherein a priority circuit for selection is provided, and one of the control power supplies in the control circuit section of each of the inverter devices is selected via the priority circuit to be the control power supply of the common control device. Control power supply method.