FI92775C - Method of using reactive power regulator - Google Patents

Description

92775

In the method of using a reactive power regulator

The present invention relates to a method for using a reactive power regulator according to the preamble of the appended first claim.

The reactive power controllers are used to control the switching on or off of the capacitors to compensate for the reactive power. The stepwise setting is characterized in that the fluorescent heater contains any area whose width is defined as 10. Using the C / K control (C stands for capacitor power and K for transformer gear ratio). The C / K value represents the reactive power of the smallest capacitor phase as determined at the input of the reactive power controller. In connection with the correct setting of the C / K value, the controller controls the on and off field of the capacitor as long as the resulting reactive power remains within the insensitivity range. When the reactive power controller controls the capacitors at different compensation powers, the stabilization time of the control circuit oscillation is at its shortest in connection with the increasing compensation power of the capacitors. Compared to the previous 20 compensation stages, a lower compensation power step can, under certain operating conditions, lead to variation in the control circuit, in which case, in general, the capacitor power of the next stage is always chosen to be at least equal to or higher than the previous compensation. Figure 1 shows the optimal C / K control for a handheld reactive power regulator. Such a case occurs, for example, when the pre-sensitivity range obtained by the C / K value is 10-20% higher than the power of the first capacitor stage.

30 There are often problems with the C / K value setting. If the C / K value is too low, the control circuit oscillates, which leads to a burn-out of the capacitor relay contacts in a short time. The C / K value that is set too high is again displayed in such a way that the • • ------ - r ~ -_ 92775 2 phase only starts in the event of a higher overcompensation or undercompensation. The reactive power controller operates satisfactorily when the C / K value remains within 1.05 to 1.95 times the phase power of the primary phase.

The object of the present invention is to remedy the above-mentioned shortcoming in the reactive power controller and to guarantee the optimal operating point setting of the controller.

This object is achieved as set out in the characterizing part of the first claim of the invention.

The invention will now be described in more detail with reference to the accompanying four figures, in which: Figure 1 shows a diagram of an optimal C / K control; Figure 2 shows a diagram of one embodiment of a reactive power controller; of the switching modes of the three source relays 20 in 1: 2: 2 increments.

As described above, the reactive power regulator oscillates too low with the set C / K value. This fact is utilized in the algorithm-25 used in connection with the adaptation of the C / K value of the reactive power controller to the control part. The starting point for this arrangement is the operating situation, in connection with which the first compensation phase is disconnected and the compensation power is required. If, after switching on the first compensation stage of the controller, it must be switched off again immediately when the resulting reactive power is outside the ka-30 passive insensitivity range (Fig. 2), the insensitivity range is too small and must be extended. This means that the C / K value must be increased. Depending on the reactive power requirement of the device, this procedure is repeated until, in the myds limit case, after the first phase-on switch-off, it is immediately switched off again. The optimal C / K value is achieved when the insensitivity range is either equal to or slightly greater than the power of the first capacitor stage.

Normally, the controller does not reach the optimal 5 C / K value during one operation step, when in addition the determined compensation power requirement of the device is required (A in Fig. 1); however, it can be assumed that the compensation power close to this point A is required once a day. In any case, the controller operates at a C / K value that is always 10 less than or at most equal to the optimal value, so that the controller has good control properties.

If the required compensation power is considerably higher than half the phase power, this fact has no slight effect on the matching algorithm. Figure 3 shows the reactive power requirement of the device 15 before switching on the smallest phase. The ratio of the capacitor powers of the connected phases in this example is 1: 1: 2: 2.

As already mentioned above, it cannot be ruled out that the compensation power 20 of the capacitors is staggered other than in ascending order. The presented different case - the first-stage oscillation - is then no longer sufficient for the assessment of the stability of the control circuit.

The criterion for the variation of the control circuit is the cyclic recovery of similar switching states of the source Rn (n = 1.2 ... denoting the number of relays) after the next 2 ”switching period. Identifying a similar switching state results in an increase in the C / K value. Figure 4 shows an example of this in connection with three outputs 30 relays R1, R2 and R3, where the oscillation circuit oscillation exceeds relay R2.

When the operating mode occurs, in which case the resulting reactive power falls within the insensitivity range, all the switching states stored until then become invalid. The new cycle 35 starts with the next state change of the output relays R1 ... R3.

«4 92775

The optimal C / K value is achieved when no similarity of the switching states occurs in the various blue operating modes of the device after each 2n (n = 1.2 ... number of output switching elements) connection.

5 In order to achieve an optimal C / K value, the matching algorithm usually requires more switching. An improvement in this situation can be achieved in such a way that the c / K value is not set to its lowest value, but to its large value when the controller is used. After the resulting parasitic-10 power is in the insensitivity range - in which case either no reactive power is required or the controller switches on the required capacitors beforehand - the C / K value decreases by an amount corresponding to the resulting reactive power. This operation can be repeated for each control process up to the time when the power of the smallest capacitor phase is higher than the insensitivity range. No start-up phase is required. The optimal C / K value is then achieved as described.

When using the control unit, the reactive power consumer can be switched off simultaneously with the switching on of the 20 smallest capacitor stages. If the C / K value has already been set to the optimal value, a higher value is now selected. To correct such an error, the C / K value is therefore reduced one or two steps per day.

25 In order to effectively improve the situation in such disturbance cases, an average check of the C / K value provides an opportunity. In addition to the C / K register, the controller contains rayds in two additional registers. The second register stores the averages of previous 30 C / K values obtained at 24-hour intervals and the third register the number N of previous observations, for example for one day or the total number of observations after the use of the fluorescent register. At the beginning of the 24-hour period, the sliding C / K value obtained by this time point is read and 35 is entered in the C / K register, possibly in one step per hour • 5 92775 times. The controller corrects this C / K value during the day if necessary. At the end of the period, a new average of this C / K value and the N-weighted old average is formed and recorded in the average register.

5 Devices with a high switching frequency have a high load on the relay contacts. In order to prevent premature wear of the relays, the switching delay time is increased from, for example, 30 seconds, e.g. in connection with more than 30 switching times in 30 minutes, to a delay time of, for example, 60 seconds-10 n. After a predetermined time, for example 3 hours, the delay time is reset to its original value, i.e. 30 seconds in the example above.

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Claims (5)

1. Procedure for using a reactor power for reactive power, where in the regulator means are wound different capacitor phases for optimal control (C / K care) of the insensitivity range, characterized by the fact that it consists of the following stages: a. Depending on the compensation state of the regulator with the aid of soul-acting couplings and switch-offs of n different compensation states, a circuit diagram of the output coupler is generated, which is immediately repeated after 2n successive state changes, as a criterion for adaptation of the C / K care, and b. this process is controlled so that until a momentary inaccuracy range (C / K care) reaches a borderline condition, which is locked as an instantaneous optimal care in an understood register. 2. A method according to claim 1, characterized in that the adaptation process is drilled in 20. the largest area of inaccuracy (C / K treatment), and that this area is reduced, depending on the resulting reactive effect, until the effect of the spoon is greater than the area of inaccuracy. 3. A method according to claim 1, characterized in that an average is formed by instantaneous optimal care observed over a period of time, which is locked into a second register. Method according to claims 1 and 2, characterized in that the number of observations is stored in a third register. 5. A method according to claims 1-3, characterized in that the sliding care locked in the second register at the beginning of each new compensation period is moved to the understand register, and immediately when it is possible on the basis of the capacitor phase. , added to this nurture a credibility phase.