JPS58218831A - Power factor improving device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a power factor improvement device that improves the power factor of electric power using a plurality of contents.

Conventionally, the circuit system shown in Figure 1A has been proposed as this type of power factor correction device. A voltage transformer that detects the load terminal voltage (hereinafter referred to as 1, P
(abbreviated as T); 3) a reactive power detection circuit that detects the reactive power of the load based on the load current and the load terminal voltage; 4)
This is a content control circuit that causes the opening/closing device 5 to open/close the content 6 in response to an increase or decrease in reactive power.

The operation of the conventional improved device constructed in this way will be explained below. The reactive power on the load is detected by a skewer which inputs the load current detected by CT1 and the load terminal voltage n'fc detected by PT2 into the reactive power detection circuit 3. The result of the accumulation is output to the content control circuit 4 as the opening/closing angle to the content switch 5,
(The content switch 5 is opened and closed by the output Tsukuda 7, and the phase leading reactive power required by the content 6 is obtained.

Next, we will discuss the control force method for the circuit shown in Figure 1A. ? J
j When compensating for reactive power using 16 contents, for example, if the ratio of phase advance capacity of content 6 is selected to be 1:2:2 as shown in Fig. In addition, it is possible to control a five-stage phase advance @ device as shown in Fig. 1B by using a power factor correction device with a six-stage power factor as shown in Fig. 1B. At the same time, the phase advance capacity of the fifth stage is inputted to the rapid increase in the lagging phase reactive power of the load. , the final phase leading capacity q5 was reached through several input stages.In addition, the lagging phase reactive power suddenly decreased from q5 to qO, resulting in 7 ICs. The phase advance capacity is switched to qO after the steps of . It shows the change in the leading phase reactive power and is the power required to compensate for the lagging reactive power of the T3tj load.In this way, the conventional power factor correction device compensates the lagging reactive power. , they were trying to improve the power factor.

Therefore, the response of conventional power factor correction devices to fluctuations in the slow-phase reactive power of the load is slow, and the phase-advance capacity is obtained in stages, resulting in high frequency of opening and closing of the switching equipment, delay in follow-up characteristics, etc. There was a lack of strength.

The present invention is designed to eliminate the above-mentioned defects.
t, content control that outputs opening/closing signals for opening and closing phase-advanced contents by opening/closing procedures. ``A first comparator, a second comparator, and a first
The purpose of this invention is to provide a low-cost power factor correction device that has a four-limit circuit and a second equal-limit circuit, greatly improves the responsiveness to fluctuations in the slow-phase reactive power of the load, and has a low frequency of opening and closing the switchgear. shall be.

An embodiment of the present invention will be explained below with reference to the drawings.

In FIG. 2, where the same parts as in FIG.
The first and second comparators of the set (among them, the ill comparator 7 and the capacitor t6 are intended to control Ql, and the second comparator 8 and the capacitor 'v6' are intended to control Ql and Q3.

In addition, when the output of the comparator 9 and 10 continues for a certain number of constants or more, there are two sets of first and second limiting circuits that output an opening/closing signal to the capacitor V6.

The 11th WII-MIl 159 is targeted at the control of Ql of the tj condenser tr6, and the control of the Ql and Q3 of the 2nd limited edition 12th Iion content 6 is targeted.Next, the operation of the present invention will be explained below. do.

In FIG. 2A, the load reactive power C'T1 is detected at t'17'2. It is detected by introducing the load current, f detected by PT2, and the load terminal' voltage into the reactive power detection circuit 3, and multiplying it by the product A. Then, the detected 1fc reactive power is compared with a preset value f'I by the first comparator 7.71 and the second comparator 8. (When the delayed phase reactive power WI loaded at ζ increases, the first comparator 7 and the second comparator 8 tj start operating, but the first and second comparators are provided with two comparison levels VL1 and VL2, respectively. The first comparator 7 controls Ql of the content 6, and the second comparator 8tj controls Ql and Q3 of the condenser 6.

Next, the operation diagram shown in FIG. 3 will be explained below.

The lagging reactive power WL is the setting level V of the first comparator 7
When L1 is exceeded, the output 1cpo of the first comparator 7 is input to the eleventh limit circuit 9. When the output i cpo of the first comparator 7 continues for more than the first town limit circuit 904 articles of incorporation T1, the input @month of Ql of the content 6 is output n. or,
When the delayed phase reactive power WL exceeds the comparison level CV2, the output 2CPO of the second comparator 8 is input to the second town limit circuit 10. Output 2CPodfi12 of second comparator 8
11'i Identification of the limit circuit 10 When 1ffT2 or more continues, the capacitors 6 Ql and Q3 are turned on and the n-condenser switching device 5 is closed, and the capacitor 6 obtains phase-advanced reactive power. The circuit 4 for supplying a plurality of capacitors has been described above, but by reversing the input polarity of the reactive power detection signal, it is possible to create an open circuit that cuts off the capacitors with exactly the same operation. In addition, when compensating for the χ lagging reactive power WL using multiple capacitors, the capacitors are
If the ratio of phase advance capacity of v6 is selected to be 1:2:2, for example, Figure B
↓It took 15 hours to open and close the capacitor
It is possible to control the phase advance capacity of the level. Further, the comparator 7 and the second comparator 8 output an output when the reactive power of the load suddenly increases and it is desired to input an additional amount of customers q5. (At ζ, the setting value of the cost constant of the four corner circuit is TI>T2, so the second cost limit circuit 10 is input to Oerlikon J Denya 6, and the output value is 1, and the Ql of capacitor 6 is
, and the input of Q3 gives priority to the Q1 area of the capacitor 6. It is possible to compensate for the lagging phase capacitance level 5 by turning on the C3 stage.Also, the lagging phase capacitance suddenly decreases from level 5 to level 0, and the leading phase capacitance is reduced by reducing the 3 stages as in the case of fcq-turning. is returned to qO. Figure 2 shows the variation of the lagging reactive power WL under the C load and the change in the leading phase reactive power that compensates for the fluctuation of ELI (in the present invention). In the figure, the It shows a simple review required to compensate for the slow phase reactive power WL.

Next, a fourth diagram is a circuit configuration diagram of a power factor correction unit showing another embodiment of the present invention. In the figure, the same parts as in FIG. 2 are designated by the same reference numerals, and the explanation thereof will be omitted.

This is a capacitor charging state monitoring circuit which monitors the charging state of recondensers 11 and 12 'v6, and outputs 1 when all banks are closed or 1 is opened, as the input state deviation angle of the capacitor 6. Also, a capacitor 6 is supplied to the switchgear 5 of the capacitor y6.
Opening/closing @ 1st and 2nd group of 2 sets of corner screws 89 and 10↓
χ is applied to the switching device 5 via the capacitor closing state monitoring circuits 11 and 12, respectively. The first condenser charge monitoring circuit 11 is designed to monitor Q and Ql of the capacitor 6, and the second capacitor charge monitoring circuit 12 is designed to monitor Q5 and Q of the capacitor 6.

The operation of the fourth prisoner A will be explained below.

Lagging phase reactive power WL of Eri load on CT1 and PT3
, and two sets of first and second comparators 7 and 8
By comparison with the preset price, two sets of 1st and 21st
The switching device 5 of the capacitor 16 is opened and closed via the Nla circuits 9 and 10, and the lagging phase reactive power WL of the load is compensated for, thereby improving the power factor. The basic operation is exactly the same as that of the above embodiment. In this actual example, the purpose is to perform compensation with high error accuracy, and the condenser f is set in the η order as described above.
6. In other words, when trying to compensate for the lagging reactive power WL using multiple capacitors Ql...Q, the capacitance of the capacitor 6 should be set to 1:1:2:
If 2 is selected, as shown in FIG. 3B, it becomes possible to control the advance rate of 6 by opening and closing condenser v6 of f'l and so1. Now, the rapid increase in the slow phase reactive power WL of the load requires the phase advance capacitor q4, and the input of the capacitor +16 Q and Q is insufficient. Furthermore, when the lagging reactive power WL of the load increases and the phase advancing capacitance q2 becomes necessary, the first comparator 7 and the second comparator 8 operate, and the output of the first The limit circuit 9 and the second fourth limit circuit w310 operate. 1 explained in the operation according to the present invention
sfl Ii times T1 and T2 are preset as T1>T2, so even though the Q of capacitor 6 and QIl are input, the Q of capacitor 6, Then, when the second time limit circuit 10 operates, the reset count which is output to the second time limit circuit 9 is set as the monitoring deflection angle of the second condenser charge monitoring circuit 12. The output of the second night limit circuit 10 is NAN
Eri stops after D times 8. Su4wachi condensation +
) Reset to the 1st 4th period k12!9 after the conditions that Q, 7A and Q of 6 have already been input j'''C and the condition that the second curfew circuit 10 is activated are satisfied. Ql of the first condenser 6 is transferred from the first dividing circuit 9 to the first condenser input monitoring snow making 11 by stopping the first condenser 6.
and output the opening/closing declination angle to the switching device Ql. Further, when Ql and Ql of the capacitor 6 are already turned on, a condenser input monitoring signal is output from the first capacitor input state monitoring area 13. Then the first comparator 7
The second IM3 limiter circuit 10 is operated with the flexibility of operation, and the opening/closing declination angle is output to the opening/closing devices of Q1 and Q2 of the content 6 via the second condenser input monitoring Mfl12. Figure 4 shows the variation in lagging reactive power of load C and the change in leading reactive power that compensates for the variation according to this embodiment; Figure 5 shows the variation in lagging reactive power WL and leading reactive power FIG. 12 is a diagram illustrating the fluctuation WH of the trough portion of the control circuit according to the present embodiment.

In addition, as mentioned above, when controlling the phase advance @ quantity in multiple stages using two sets of comparators and four corner circuits, adding a condenser puncture comparator and a limiting circuit will invalidate the delay phase of the load. It is easily possible to make the response to power faster. Furthermore, it is also possible to reduce the frequency of opening and closing of the opening/closing device.

As described above, the present invention (= engineering) consists of a comparator and a four-corner circuit that operate by comparing the level of the detected f'Ifc reactive power in order to speed up the control response of the lagging capacitor to fluctuations in the lagging reactive power of the load. , I controlled the timer circuit (two sets) using a circuit that monitors the input state of the phase-advancing capacitor 1, and so that the reset @ signal was applied at an arbitrary timing. This significantly reduces the frequency of opening/closing of the switching device, contributing to longer life of the device, and improves the accuracy of phase advance control L', resulting in a significant power factor improvement device with high reliability.

[Brief explanation of the drawing]

Figure 1 is a circuit diagram and explanatory diagram of the contents of the conventional power factor correction equipment, Figure 2 is a circuit diagram and explanatory diagram of the contents of the power factor improvement device of the present invention, and Figure 3 is an explanatory diagram of the operation of the power factor improvement device of the present invention. ,
A fourth diagram is a circuit configuration diagram and an explanatory diagram of contents of a power factor correction device showing another embodiment of the present invention, and a fifth diagram is an explanatory diagram of the operation of FIG. 4. . 1... CT for load current detection, 2... PT for load end pre-voltage detection, i output, 3... Reactive power detection circuit, 4...
... Content 1 control circuit, 5... Condenser opening/closing device, 6... Content, 7... Comparator 1.8.
...Comparator 2.9...Four corner circuit 1.11...
1st condenser charging monitoring device, 12...2nd condenser charging monitoring device. Agent Tsukuda Kuzuno (1 person) 1li1 Figure 83

Claims (1)

[Claims] (1) A power factor improvement@installation system that applies and shuts off multiple contents to improve the power factor of the power system, a reactive power detection circuit that detects the reactive power of the power system, and the capacity of the content. a plurality of comparison circuits each having a different comparison level corresponding to the type and quantity of the comparison circuits; and a plurality of delay circuits corresponding to the plurality of comparison circuits that apply Erie foot delay operations to the operational outputs of the comparison circuits. , wherein the reactive power changes and exceeds the comparison level of the comparison circuit, and the delay circuit other than the delay circuit operates while opening and closing the corresponding content via the delay circuit corresponding to the comparison circuit with low operation. The special purpose of the power factor modification was to reset the other delay circuits in the circuit, and to shorten the length between the delay sections of the delay circuit, which had been subjected to R7, in order from the smaller force of each condenser puncture to the larger force. 1 (21) If the detected value of the reactive power exceeds a predetermined comparison level of the comparison circuit, the content bank corresponding to the comparison level has already been fully loaded and opened. Power factor improvement according to claim 1, characterized in that, when 1 is satisfied, a condenser other than the condenser number corresponding to the comparison level of the comparison circuit can be opened and closed. Device.