JPH0730552U - Control unit for control center - Google Patents

Abstract

(57) [Summary] [Purpose] To provide a control unit for a control center that is intelligent. [Structure] Current signal input circuits 18, 19, 20, an AD conversion circuit 25, and a contact signal output circuit 34 are provided, and an input unit 28 is provided.
The abnormal state of the load is detected in response to the switch instruction input by the input of or, and the open / close control of the switch 13 is performed by the output signal of the contact signal output circuit. [Effects] Load switching control, protection, current measurement, without using individual protection relays, ammeters, and operation time meters.
It is possible to integrate operating time. Further, a large number of auxiliary relays for forming the sequence circuit are unnecessary.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a control unit for a control center that controls opening / closing and protection of an electric motor, a transformer, an electric light load, or the like.

[0002]

[Prior art]

 Fig. 4 shows the structure of the control unit for the control center in the conventional equipment equipped with an electric motor, transformer or electric light load. In FIG. 4, the thermal OC relay 1 detects a heating state due to overload of the electric motor, for example, to protect the electric motor, and the static earth relay 2 detects electric leakage and protects it. The operating time meter 3 mechanically integrates the operating time of the electric motor and the like to obtain and display the integrated operating time. The ammeter 4 measures and indicates the load current. Auxiliary relays 5a, 5b ... 5m and 6a, 6b ... 6n constitute a sequence circuit together with a thermal OC relay 1 and a static earth leakage relay 2 to control the opening and closing of an electric motor, transformer or light load. And protect.

[0003]

[Problems to be solved by the device]

 However, in such a conventional control unit for a control center, the various protective relays and ammeters are individual analog type devices, and these have only been combined into one unit. Therefore, the connection to the CT (current transformer) must be done separately, and there is no organic coupling between each device, so there was a wasteful component of the control unit as a whole. In addition, a large number of auxiliary relays were required to configure the sequence circuit together with various protective relays, the control unit was large in size, the installation space was large, and the sequence circuit design and manufacturing man-hours were complicated. Furthermore, the display of the operating hour meter, the indication of the ammeter, and the status display of various protective relays are performed individually for each device, so it was not easy to confirm them, and it was not possible to display them on the panel.

An object of the present invention is to provide a control unit for a control center which solves the above-mentioned various problems and is intelligent.

[0005]

[Means for Solving the Problems]

 A control unit for a control center according to claim 1 of the present invention comprises a current signal input circuit for inputting signals of currents of respective phases and zero-phase currents through which a load current flows, and AD conversion for converting these current signals into digital data. Circuit, a contact signal output circuit that outputs a contact signal including a signal for controlling the switch to open and close the load current, and the input from the manual input section, and settling for detecting the occurrence of an abnormal state of the load Settling means for setting a value, and abnormality detecting means for detecting the presence or absence of an abnormal state of the load based on the current value and zero-phase current value of each phase obtained by the AD conversion circuit and the settling value, A switch control means for controlling the switch by outputting a contact signal from the contact signal output circuit according to an opening / closing instruction input to the switch or the abnormal state detection result, and the settling value Other comprises a display control means for displaying on the display the detection result of the abnormal state.

A control unit for a control center according to a second aspect of the present invention is the control unit according to the first aspect, further comprising load current value calculating means for calculating a load current value from the current value of each phase, The display control means displays the load current value on the display.

A control unit for a control center according to claim 3 of the present invention is the control unit according to claim 1 or 2, wherein the operating state of the load is determined from the current value of each phase or the load current value. Means for integrating the operating time and calculating the integrated operating time, and a non-volatile memory for storing the integrated operating time are further provided, and the display control means displays the integrated operating time on the display.

A control unit for a control center according to a fourth aspect of the present invention is the control unit according to the first, second or third aspect, wherein a contact signal input circuit for inputting a contact signal from the outside and a predetermined sequence are used. And a contact signal control means for outputting a contact signal from the contact signal output circuit in accordance with a contact signal input from the contact signal input circuit or a detection result of the abnormal state.

[0009]

[Action]

 In the control unit for a control center according to claim 1 of the present invention, the current signal input circuit inputs the signals of the respective phases of the load current and the zero-phase current, and the AD conversion circuit outputs these current signals as digital data. Convert to. The contact signal output circuit outputs a contact signal including a signal for controlling a switch for switching the load current to the outside. The settling means reads the input from the manual input section and sets a settling value for detecting whether or not an abnormal state of the load has occurred. Then, the abnormality detecting means detects whether or not an abnormal state of the load has occurred based on the current value and zero-phase current value of each phase obtained by the AD converting means and the set value. The switch control means controls the switch by outputting a contact signal from the contact signal output circuit in response to an opening / closing instruction input to the switch or an abnormal state detection result. Further, the display control means displays the settling value or the detection result of the abnormal state on the display. In this way, the opening / closing of the switch is controlled according to the opening / closing instruction input to the switch, and the switch is controlled according to the detection result of the abnormal state of the load. In addition, the set value for abnormal load detection or the detection result of abnormal condition is displayed.

In the control unit for a control center according to claim 2, the load current value calculating means calculates the load current value from the current value of each of the phases, and the load current value is displayed on the display. As a result, the common current signal input circuit is used to detect an abnormal state of the load, protect the load, and measure the load current.

In the control unit for the control center according to the third aspect, the integrated operating time is calculated, stored in the non-volatile memory, and the calculated integrated operating time is displayed on the display. As a result, the operating time is integrated based on the signal input using the common current signal input circuit, and the value is displayed on the predetermined indicator.

In the control unit for a control center according to claim 4, the contact signal input circuit inputs a contact signal from the outside, and the contact signal control means detects the contact signal input from the contact signal input circuit or the detection result of the abnormal state. In response to this, a contact signal is output from the setting signal output circuit. Thus, the sequence control of the device including the switch connected to the contact signal input circuit and the contact signal output circuit is performed according to a predetermined sequence.

[0013]

【Example】

 FIG. 1 is a block diagram showing the configuration of a control unit for a control center which is an embodiment of the present invention. In FIG. 1, 11 is a control center control unit, and 14 is an electric motor to be controlled. Reference numeral 12 is a circuit breaker that protects the electric motor 14 from an overcurrent flowing through the motor 14 independently of the control unit 11. A switch 13 is controlled to open and close based on the output of the control unit 11. CT1 and CT2 are current transformers that detect current signals of respective phases flowing through the electric motor 14, and ZCT is a current transformer that detects zero-phase current. In the control unit 11, the input circuits 18, 19 and 20 are CT1, CT2 and ZCT input circuits, and generate voltage signals proportional to respective current signals. The sample hold circuits 21, 22, 23 sample and hold the output signals of the input circuits 18, 19, 20. The multiplexer 24 selects one of the sample hold circuits 21, 22, and 23. The AD converter 25 converts the signal given by the multiplexer 24 into digital data. The CPU 26 sequentially switches the multiplexer 24 and reads the digital data converted by the AD converter 25. The display unit 27 is a multi-digit numerical display unit composed of an LED, and switches and displays a set value, whether or not an abnormal state has occurred, a load current value, an accumulated operating time, etc., in accordance with the output signal of the CPU 26. The input unit 28 is used as a manual input unit for inputting an opening / closing instruction of the switch 13, inputting the set value, and instructing the display unit 27 to switch display contents. The clock counter 29 performs a clock operation independently of the CPU operation. The CPU 26 measures the passage of time by reading the contents of the clock counter 29. A circuit that generates a timing signal of a constant cycle (for example, a one-second cycle) independently of the clock of the CPU is provided, the CPU is interrupted by this timing signal, and the CPU counts time by the interrupt processing. You may do it. A program to be executed by the CPU 26 is written in the ROM 30 in advance. When executing the program, the RAM 31 temporarily stores various data such as digital data of each signal converted by the AD converter 25, arithmetic processing for detecting the occurrence of an abnormal state of load, load current value calculation processing, and operating time. It is used as a working area for various calculation processes such as multiplication and sequence control. The EEPROM 32 stores the set value and the integrated operation time. The contact point signal input circuit 33 inputs a plurality of contact point signals including a contact point signal indicating the state of the circuit breaker 12 from the site panel, and the CPU 26 reads the state of each contact point signal via the contact point signal input circuit 33. The contact signal output circuit 34 outputs a plurality of contact signals including a break command for the circuit breaker 12 to the site panel. The CPU 26 controls ON / OFF of each contact signal to the site panel via the contact signal output circuit 34. The power supply circuit 35 inputs a commercial power supply AC110V and supplies a predetermined power supply voltage to each part of the control unit 11.

Next, a processing procedure of the control unit for the control center shown in FIG. 1 is shown in FIGS. 2 and 3 as a flow chart. First, the processing shown in FIG. 2 is performed at the sampling timing of the current signal as shown in FIG. 2, and the processing shown in FIG. 3 described later is performed at other timings. At the sampling timing of the current signal, first, the AD conversion result of the current signal of each phase is read (n1 → n2). Then, the presence or absence of an instantaneous overcurrent state for instantaneous overcurrent protection is detected based on the current value of each phase (n3). If it is determined that the instantaneous overcurrent state is present, the instantaneous overcurrent protection process is performed by displaying an error content indicating that fact on the display and outputting a contact signal for opening the switch 13 (n4 → n5 → n6). Then, a calculation for detecting the timed overcurrent is performed (n7). If the timed overcurrent state is detected, the content indicating that is displayed on the display and the timed overcurrent protection process is performed (n8 → n9 → n10). Further, subsequently, a calculation for detecting an open phase condition is performed (n11). If the open phase condition is detected, the content indicating that is displayed on the display and the open phase protection process is performed (n12 → n13 → n14). Thereafter, in the same manner, the antiphase state is detected and protected, and the ground fault state is detected and protected (n15 to n22). Further, if the state of the circuit breaker 12 is read from the contact signal input circuit 33 and regarded as a circuit breaker, the content indicating that is displayed (n23 → n24 → n25). If it is in the closed state, a fixed time is added to the integrated operation time to update the integrated operation time (n26). After that, a contact signal is input from the contact signal input circuit, and sequence control calculation is performed based on the contact signal and the already detected detection results of various abnormal states (n27 → n28). Then, sequence control is performed by outputting a contact signal to the site panel via the contact signal output circuit (n29).

At a timing other than the sampling timing of the current signal, as shown in FIG. 3, first, the input content from the key input unit is read (n31). If it is a key operation for inputting various set values such as the upper limit current value and operating time, this is read and stored as a set value (n32 → n33). Then, a value 2 to m corresponding to the type of settling value is set to the value DM indicating the display mode (n34). If the display switching key is operated, the value DM representing the display mode is incremented by 1 (n35 → n36 → n37). However, when DM = m, 0 is set to DM (n38). For other key inputs, a process corresponding to a predetermined key operation is performed (n39).

After that, the content corresponding to the value of DM is displayed. For example, if DM = 0, the load current value is displayed on the display (n40 → n41). If DM = 1, the integrated operation time is displayed on the display (n42 → n43). Further, if DM = 2 to m, the set value of the type corresponding to the value is displayed (n44 → n45). Further, in the processing of steps n5, n9, n13, n17, n21 or n25 in FIG. 2, a value other than 0 to m is set to the value DM indicating the type of display content, and in step n46 in FIG. Perform processing.

In the example shown in FIG. 3, the display contents are cyclically switched and displayed by a single key operation. However, by operating the individual keys indicating the display type, The contents may be displayed.

[0018]

[Effect of device]

 According to the control unit for a control center according to claim 1 of the present invention, the current signal input circuit, the AD conversion circuit, the contact signal output circuit, the settling means, the abnormality detection means, the opener control means and the display control means are each organic. Since the load is opened / closed and protected by being combined with each other, the load can be opened / closed and protected without using individual protective relays.

According to the control unit for the control center of the second aspect, since the load current value is displayed on the display unit that displays the detection result of the set value or the abnormal state, an individual ammeter is not required, and The visibility is also improved.

According to the control unit for a control center of the third aspect, since the integrated operating time is calculated by detecting the load current, a separate operating time meter is not required and its visibility is improved.

According to the control unit for the control center of the fourth aspect, since it functions as a sequencer, a large number of auxiliary relays for configuring the sequence circuit are not required, and the overall size of the sequence circuit is reduced. Design and manufacturing man-hours are shortened.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a control center control unit according to an embodiment of the present invention.

FIG. 2 is a flowchart showing a processing procedure of a control unit for control center shown in FIG.

3 is a flowchart showing a processing procedure of a control unit for a control center shown in FIG.

FIG. 4 is a block diagram showing a configuration of a conventional control unit for a control center.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI technical display location H02H 7/08 J 8936-5G

Claims (4)

[Scope of utility model registration request] 1. A current signal input circuit for inputting signals of currents of respective phases in which a load current flows and zero-phase current, and an AD conversion circuit for converting these current signals into digital data.
A contact signal output circuit that outputs a contact signal including a switch control signal that opens and closes the load current to the outside, and reads the input from the manual input section to set the set value for detecting whether or not an abnormal state of the load has occurred. Settling means for detecting the presence or absence of an abnormal state of the load based on the current value and zero-phase current value of each phase obtained by the AD conversion circuit and the settling value; and the switch. Switch control means for controlling the switch by outputting a contact signal from the contact signal output circuit according to an opening / closing instruction input or the abnormal state detection result, and the settling value or the abnormal state detection result is displayed on a display. A control unit for a control center, comprising: 2. The control center according to claim 1, further comprising load current value calculating means for calculating a load current value from the current value of each phase, and the display control means displaying the load current value on the display. Control unit. 3. A means for determining an operating state of a load from the current value of each phase or a load current value, adding up time during operation to calculate an integrated operating time, and a nonvolatile memory for storing the integrated operating time. A memory is further provided, and the display control means displays the integrated operating time on the display.
Or the control unit for the control center according to 2. 4. A contact signal input circuit for inputting a contact signal from the outside, and from the contact signal output circuit according to a contact signal input from the contact signal input circuit or a detection result of the abnormal state according to a predetermined sequence. A contact signal control means for outputting a contact signal, further comprising:
The control unit for the control center according to item 2 or 3.