SU1290384A1 - Method and apparatus for checking and controlling operation of electric network - Google Patents

Abstract

The invention relates to electrical engineering and measurement technology and is intended to monitor and control the maximum of the electrical network of an enterprise of electrical consumers. The device provides high accuracy. The essence of the method consists in comparing the control voltage with predetermined levels and in analyzing the duration of exceeding these levels. The monitored voltage is generated by converting the mains parameters and subtracting the nominal value from it. The monitored voltage is valid only during the hours of maximum power consumption. The device contains a sensor of 8 time intervals, a converter 1 of the parameters of the power grid to voltage, comparators 2 and 3, amplifiers 4 and 5, element I 6, element 7 of the time delay, signaling devices 9-11 and inverter 14. 2 pts and 3 z. p. f-ly, 1 ill. ND; about o 00 00 1

Description

The invention relates to electrical engineering, namely, to measuring equipment, and is intended to monitor and control the maximum load of enterprise-electric consumers.

The purpose of the invention is to improve the accuracy of the device.

The drawing shows a functional diagram of the device for implementing the method.

The device contains a converter 1 of the power grid parameters in voltage, the first 2 and second 3 comparators, the first 4 and second 5 amplifiers, element 6, time element 7, sensor 8 time intervals, first 9, second 10 and third 11 alarm devices, node 12 disconnecting part of the load, node 13 including part of the load and inverter 14.

To offset the starting current between the output of the second comparator 3 and the input of the first amplifier 4, an additional time delay element 15 may be additionally included.

To adjust the return ratio of the comparators, the output of the second comparator 3 or the output of the first amplifier 4 is connected to the input of the comparator 3, and the output of the first comparator 2 is connected to one of its inputs.

Current transformers with a rectifier and filter at the output or a current and angle control unit between current and voltage can be used as a converter. In this case, the converter includes a current transformer, a voltage transformer, and current and angle converters to a second voltage. Comparators 2 and 3 can be made on dinistors, analogs of unijunction transistors, operational amplifiers, and other elements. Amplifiers 4 and 5, Inverter And, Elements 6 and Time Element 7 are executed on logic elements. Nodes 12 and 13 on switching on or off the load are performed on relays, semiconductor elements or their combinations depending on the method of acting on the load. Sensor 8 can be performed, for example, on a clock with contact outputs; 1, a- or according to any other scheme.

The implementation of the monitoring method by the device is as follows.

During hours of maximum travel, sensor 8 includes a converter 1 that controls one or more network parameters (for example, current or current and the angle between current and voltage). They are converted into a common control voltage, compared with the first reference voltage, and when the latter is exceeded, a second voltage is generated at the output of converter 1, which is fed to the inputs of Comparators 2 and 3. The reference level of the second com:

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ten

15

20

25

thirty

35

40

50

Parator 3 is formed proportional to, for example, a load 5% lower than the allowable1 value of the maximum load. The reference level of the first comparator 8 is formed proportional to the permissible maximum load or most of it, for example by 2%.

The second voltage is compared with the second and third reference voltages of the comparators 3 and 2, respectively. When exceeded, the second voltage of the second comparator voltage of the comparator 3 turns on the alarm 9 and warns the staff about the load value, and when the third reference voltage of the comparator is exceeded 2 form a predetermined time delay by element 7 after switching on element 6. While maintaining the specified load mode and after the end of time delay, a part of the load is disconnected from the network by the disconnecting node 12, which turns on th amplifier; 5. Simultaneously with this, a second detector 10 is switched on and the third detector I1 is disconnected with node 13 by controlling inverter 14, and the voltage is applied to the input of element I 6 from the output of the first amplifier 4.

To eliminate the self-oscillating mode, the disconnection of a part of the load is fixed by applying output voltage to the inputs of comparators 2 and 3, and the most retaining of the signalization of the injector 9 and W and the disconnection unit 12 in the on state, and the signal of the attorney 11 and the enablement unit 13 in disconnected.m while reducing control from the output of the transducer; 1 1 due to disconnection of a part of the load. With cf | izhepepi load for the formation of a time delay due to feedbacks of the comparators 3 to 2 ensure the return of the system to control and control to the initial state.

After the hours of the maximum load have passed, sensor 8 disconnects converter i and ensures that the previously disconnected part of the load is switched on using the turn-on unit 13 by disconnecting the comparators and the inverter 14 with a running signal. One-pass control with this includes c.4rnajin3aT (jp 1 1 The inclusion of part of the load can also be carried out manually. In this case, the device circuit is controlled, but A01-; there are other costs.

When 11) the evening maximum of the load is loaded or the first np ((- (, i) is repeated.

Claims (7)

1. (lyusob monitoring and control of the electrical network, consisting in ripeo6-) setting parameters of the controlled network amg. stress and shaping li the error signal by subtracting from the amplitude of the voltage of the first reference voltage, characterized in that, in order to increase the control accuracy, a sequence of pulses is formed from the error signal, whose amplitude is equal to the error signal amplitude, the beginning and duration of the power supply during days, for each pulse, the instantaneous value of the voltage is compared with the second reference voltage and, in the event of an excess, forms a signal control simultaneously for each pulse, compare the instantaneous value of the voltage with the third reference voltage and, if exceeded, compare the time interval exceeding the instantaneous voltage value with a predetermined time interval and, if it is exceeded, disconnect part of its load from the mains each pulse of the sequence connect part of the previously disconnected load of the power grid. 2. Method 1, characterized in that the ratio of the second and third reference stresses to the reference value of the error signal does not exceed respectively the values 1.00-1.02 and 1.00-1-1.05. 3. Method according to claim 1, characterized in that the time interval is compared with the instantaneous value of the voltage of the pulses of the second reference voltage with a predetermined time interval and, if it is exceeded, a control signal is generated. five 4. A device for monitoring and controlling the operation of the mains, contains a mains voltage to voltage converter, the output of which is connected to the first input of the first comparator, the output of which is connected to the first input of the AND element, and a time interval sensor, characterized in that devices, a second comparator is introduced into it, a time delay element, 0 amplifiers, inverters and signaling devices, the output of the time interval sensor is connected to the control input of the mains voltage to voltage converter, the output of which is connected to the first input of the second comparator, the output of which is connected to the input of the first signaling device through the first amplifier and to the second input of the And element, the output which through the element of time delay is connected to the input of the second amplifier, the output of which is connected to the second The 0 inputs of the comparators, with the input of the second detector and with the input of the inverter, the output of which is connected to the input of the third detector, the outputs of the second amplifier and the inverter are outputs of the device. 5. The device according to claim 4, characterized in that an additional time delay element is introduced, the output of which is connected to the input of the first amplifier, the output of the second comparator is connected to the input of an additional time delay element. 6. The device according to claim 4, characterized in that the output of the first amplifier is connected to the third input of the second comparator. 7. The device according to claim 4, characterized in that the output of the first comparator is connected to its third input.