The method of controlling the reactive power compensator

 

(57) Abstract:

The essence of the invention: in the compensator containing parallel connected inductive element, a counter-parallel thyristors, capacitor battery and switches compensator capacitor Bank, the capacitor discharge batteries carry a counter-parallel connected thyristors controlled pulses synchronizing with the following frequency L - C circuit formed by the inductance and capacitance of the compensator and the rapid discharge a total current of condenser battery within a few tens of periods of oscillations for different values of L and C circuit that is a few seconds. 2 Il.

The invention relates to electronics, in particular for electricity, and can be used in a static reactive power compensator for transmission lines.

A known method of controlling the reactive power compensator in which the discharge of condenser battery compensator is performed via the discharge resistors connected parallel to the capacitors of the capacitor battery.

The disadvantages of this method are the low reliability because of the large to the E. great cooldown to re-enable the capacitor Bank.

A known method of controlling the reactive power compensator, which provides a rapid discharge of the capacitor battery, in which the functions of the network parameters support angle control valves, including their frequency network;

before switching to reduce the current through the switch compensator to the minimum value by the influence of the angle control of the thyristors;

disconnect switch compensator;

since the circuit breaker compensator for discharge of condenser battery include thyristors with its own frequency compensator defined by the parameters L and With the compensator;

measure the voltage level on the capacitor battery;

compare it with the minimum specified value;

if equality disconnect switch capacitor banks

restore the original frequency turn-off thyristors with the desired angle control and include a switch to compensate for Satoru.

However, the known method has the lack of reliability of the control compensator of reactive power due to the unreliability of the thyristor control at the discharge condensator is TKE control changing the frequency of the synchronization pulse thyristor control depending on changes of the parameters of the compensator. In addition, the need to measure the voltage on the capacitor battery and comparing the measured value with the set to determine when the end of discharge of condenser battery also reduces the reliability of the compensator control.

The aim of the invention is to improve the reliability of compensators due to the formation at the discharge of the capacitor battery of the respective synchronization signals, providing the inclusion of counter-parallel connected thyristors with a variable inductance or capacitance of the compensator.

This is achieved by the fact that after the circuit breaker compensator produce launch clock pulse and serves it on the counter-parallel connected thyristors, emerged from the half-wave current at the time of its completion allocate current clock pulse and serves it on the counter-parallel thyristors, etc. to reduce the signal level at the output of the sensor parameter, proportional to the current compensator to a minimum level corresponding to the holding current of the thyristor, so each subsequent half-wave current is started by the previous wave of the current, i.e., the time of occurrence of each of the next half-wave of toklas control thyristors when changing the natural frequency of the compensator, i.e. when you change the parameters L, With compensator, so there is no need in their control and development control changing the frequency of the control pulses of the thyristors when changing the parameters of the compensator, which increases the reliability of the compensator control.

In addition, the use of the current signal, allows, in addition to obtaining the required synchronization of the control pulses of the thyristors to provide a rapid discharge of the full current of the capacitor Bank to the minimum level defined by the holding current of the thyristor and eliminates the need to measure the voltage of the capacitor battery, which also increases the reliability of the control capacitor.

In Fig. 1 shows one example of the use of the method that explains the device of Fig. 2 is a timing diagram explaining the operation of the device.

The device consists of connected to the network through the switch 1 of the compensator 2, consisting of a series connected inductive element 3 and the counter-parallel connected thyristors 4 and is connected thereto in parallel through the switch 5 capacitor Bank 6, controller 7 connected to the network through the sensor 8 parameter Setty which are connected, respectively, by differentiating the elements 12 and 13 to the 1-th and 2-th inputs of the element IL 14, 3-d input of which is connected through a differentiating element 15 and block 16 of the contact switch 1 to the source voltage E, the 4th input of which is connected through the block 17 of the contacts of the switch 1 to the output of the controller 7, the inputs of the Comparators 10 and 11 are connected through the block 18 of the contacts of the switch 1 to the output of the current sensor 9, the output of the OR element 14 is connected to the input of the amplifier-shaper 19 pulses, the output of which is connected with the control electrodes of the counter-parallel connected thyristors 4, either directly or through the host 20 galvanic isolation, for example a transformer.

The operation of the device is as follows.

In the regime of network parameters, such as voltage, switch 1 and switch 5 is turned on. When the switch 1 in the blocks 16, 18 contacts are open, the unit 17 contacts are closed and the current through the inductive element 3 is determined by the synchronization pulses appearing on the output of the controller 7 according to the signals of the sensor 8 voltage. The current through the capacitor battery 6 is determined by the value of its capacitance and the voltage whose period is TS. Before disconnecting capacitor Bank 6 the current through the inductive element set according to the signal controller with many brand is>produce the circuit breaker 1. Through the time corresponding to the delay time tCat the moment of time t1opened in block 17 contacts 17 1 and closed contacts in blocks 16 and 18 of the switch 1. When the circuit in block 16 of the contacts on the output of the differentiating element 15 appears starting sync pulse U 15 passing through the element IL 14 (U 14), and after amplification in the amplifier-shaper 19 pulses (U 19) is supplied to the control electrodes of the meetings - but-parallel connected thyristors, ensuring their inclusion on the voltage UKBcapacitors battery 6. You receive 1-I positive half-wave current i, which is the output of the sensor 9 is supplied through the closed contacts blocks 18 to the input of the Comparators 10 and 11, causing the switching comparator 10. At the end of the positive half-wave current of the differential voltage levels on the output of the comparator 10 is differentiated and differentiating element 12 and the appearing of the current clock pulse U 12 is fed through the OR element 14 (U 14) on the amplifier-shaper pulse 19 (U 19) and then through the node galvanic isolation 20 on the control electrodes of the thyristors 40 ensuring their inclusion and the appearance of a negative half-wave current, which causes the switching comparefiletime differentiating elements 13 and introduced the current clock pulse U 13 is fed through the OR element 14 (U 14) on the amplifier-shaper pulse 19 (U 19) and then through node 20 galvanic isolation on the control electrodes of the thyristors 4, ensuring their inclusion and the appearance of the positive half-wave current, which causes the switching comparator 10, and so on, Then the processes are similar up until the voltage UKBon the capacitor battery 6 decreases to a minimum level UKBminthat is until the voltage at which the current Iminthrough the thyristors 4 reaches the value of holding current Ibeatsand the thyristors are not included (time t2). Then restore the original the switching frequency of the thyristors with the desired angle control and include switch compensator.

The oscillatory discharge of a condenser battery 6 to the inductive element 3 through a counter-parallel connected thyristors 4, followed by the frequency f = defined by the parameters L, With compensator provides current pulses U 14 formed on the moments of the end of the half-wave current. Therefore, the frequency of the pulse shaping control thyristors at the discharge of the capacitor battery is always equal to the natural frequency ftocircuit formed by the capacitor Bank 6 and the inductive element 3 regardless of changes in the parameters of the circuit (the value of the capacitance of condenser battery 6 and the inductance value of the inductive is Atara with tunable frequency and control systems, regulating the repetition frequency of the clock generator and their phase position relative to the voltage on the thyristor, which increases the reliability of the compensator control.

The formation of the current pulses of the half-wave current also allows you to ensure the maximum inclusion of thyristors with a minimum voltage on the capacitor battery, because to ensure complete discharge of the capacitor battery without direct measurement of the voltage on the capacitor battery, which also increases the reliability of the control joints.

The method of controlling the REACTIVE POWER COMPENSATOR, connected to the network through the switch and contains parallel connected adjustable in opposite parallel connected thyristors inductive element and through the switch capacitor battery, in which the functions of the network parameters support angle control of the thyristors, including their frequency AC power, and produce switching of the switches so that before switching to reduce the current through the switch compensator to a minimum by the influence of the angle of thyristor control, disconnect switch compensator off and include tire lower signal strength parameter to a minimum level, then restore the original the switching frequency of the thyristors with the desired angle control and include switch compensator and switch capacitor battery, characterized in that after the circuit breaker compensator form the launch clock pulse and serves it on a counter-parallel connected thyristors, at the end of each half-wave discharge current of condenser battery form the synchronization signals and applying them to the said thyristors to reduce the signal level parameter, proportional to the current compensator, to a minimum level corresponding to the holding current of the thyristor.

 

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