JPS60148342A - Stationary reactive power regulator - 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] [Technical field to which the invention pertains] The present invention relates to a static non-active power adjustment device that is directly connected to a high-voltage power transmission line and is used mainly to compensate for phase-advanced reactive power generated in the power transmission line. Regarding.

[Prior art and its problems]

In recent years, a static static power compensator (approximately @5vC) using a thyristor has been used as a #M device to stabilize the voltage of the power system.
has been put into practical use. This type of device is often connected to long-distance power transmission lines, and therefore it is desired that the device be economical when directly connected to an ultra-high voltage system.

FIG. 1 is a connection diagram of a conventionally known device. In the figure,
The slow phase capacitance adjustment circuit 1 consists of a series circuit of a reactor 2 and a thyristor switch 3 connected in antiparallel, and each phase phase capacitance 1llll adjustment circuit is delta-connected and connected to the three-phase power system MIG. In this case, the current flowing through the reactor 2 is turned on and off by controlling the phase of the thyrisk switch 3.
The lagging phase capacitance can be adjusted by off-controlling, but by controlling the phase of the sirisk switch 3, the currents lu, lv, and IW flowing through each phase of the lagging phase capacitance adjustment circuit 1 contain many harmonics outside the fundamental wave field. Contains ingredients. 4 is a filter for absorbing high and harmonic components, which consists of a series resonant circuit of a reactor 6 and a capacitor 6, and has a lagging capacitance Ill.
By providing multiple sets of harmonic filters 4 having different resonance frequencies corresponding to the orders of harmonics generated in the adjustment circuit,
High-frequency 'rf flowing into the power grid! It is configured to suppress the 1fIl flow below the value allowed by the system. With this configuration, the phase-advanced reactive power of the power system 10 can be compensated for by the phase-delay capacity generated by the phase-delay capacity adjustment circuit W51, and the harmonic current can be absorbed by the harmonic filter 4. However, since the terminal voltage of the regulator is suppressed by the system a voltage, the energizing current 1p of the slow phase power regulator circuit
u, Ipv, and fpw are uniquely determined by the capacity of the accelerator 2. On the other hand, the f8 current capacity that can be energized by the cyrisk switch 3 is the above-mentioned s'4 current 1pu+
Although it is generally larger than Ipv and Ipw and has sufficient margin for current capacity, the high system am pressure increases the number of thyristor elements connected in series, making it difficult to energize the thyristor switch depending on the power status of the device. The disadvantage is that the afs force capacity is becoming larger and larger, which is economically disadvantageous. Furthermore, the capacitor 6 and reactor 6 constituting the harmonic filter 4 also have the disadvantage that the device becomes large in size in order to provide insulation that can withstand the system a voltage, and accordingly, the equipment becomes expensive.

Fig. 2 is a connection diagram of an improved conventional reactive power H difference device. In Fig. 0, 7 is a three-phase two-turn IW transformer; ! 8 is delta-connected and connected to the power system via a bus 10, and a silisk switch 11 is connected to the secondary winding a19 for each phase winding. The harmonic filter 4 is configured to be directly connected to the power system as in the conventional device shown in FIG.
By doing this, the 3rd high m-wave current surrounds the primary winding and does not flow into the power system, so a high-order harmonic filter other than the harmonic filter for absorbing the 3i% counterfeit wave is installed. It will be done. When the rated current flows through the transformer n7, the voltage drop (impedance voltage) due to the leakage impedance between the primary and secondary 4111M is, for example, 1 of the rated voltage of the device.
00%, the phase angle of the si-risk switch 11 is controlled by a control device (not shown), and as a result, the secondary winding of the transformer repeats short circuits at predetermined intervals, so that the transformer A current corresponding to the rated current of the device regulated by the impedance voltage flows into the primary side of the device 7, and a predetermined phase power can be generated. In addition, since the voltage and current of the secondary winding [9] can be set arbitrarily under the condition that the product of both is approximately equal to the device capacity, the current capacity and cutting voltage of the thyristor element used in the thyristor switch 11 should be taken into consideration. The voltage and current values can be set to minimize the number of elements connected in series. Therefore, compared to the conventional N-type construction shown in FIG. 1, it is possible to make the thyristor switch 11 more durable than the conventional type shown in FIG. However, in a device configured in this way, the primary winding is connected in delta to prevent the third harmonic sM6 from flowing into the power system, and this device is used in ultra-high voltage power systems that generate a lot of phase-advanced reactive power. When connected to a transformer, each phase winding of the -order There are problems in that the device is large and expensive, and since the harmonic filter 4 is directly connected to the ultra-high voltage power system, there are drawbacks similar to those described in the conventional structure shown in FIG.

[Purpose of the invention]

The present invention was made in response to the above-mentioned situation, and even when used directly connected to a single ultra-high voltage system that generates phase-advanced reactive power, #! It is an object of the present invention to provide a stationary power consumption IW adjustment device that does not cause an increase in the size of the equipment or economic disadvantage.

[Key points of the invention]

According to the present invention, the above-mentioned object is achieved by using a three-winding transformer with high impedance between the negative and secondary windings, and by dividing the on/off portion of the si-risk switch provided on the secondary side into a slow phase state. The dynamic force is adjusted to compensate for the phase-advanced reactive power generated in the power system, and the harmonics are absorbed by the tertiary winding with a delta tJ line and the harmonic filter installed on the tertiary side, and high 1i waves are transmitted to the power system. In addition to preventing leakage, the harmonic filter is made smaller by setting the voltage of the tertiary winding to an optimal value that takes into account the insulation cost of the filter, and the negative winding is star-connected to simplify insulation. achieved.

[Embodiments of the invention]

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

FIG. 3 is a connection diagram of a device including an embodiment of the present invention. In FIG. A star-connected primary winding 28 connected to an ultra-high voltage power system 820 that generates phase-advanced reactive power and a secondary winding 29 formed so as to have high impedance between the -order winding. An anti-parallel connection switch 11 is connected to each phase winding of the secondary winding 29, and a harmonic filter 24 consisting of a series resonant circuit of an axle 25 and a capacitor 26 is connected to the tertiary winding 30. is connected. In the static non-active power HN device configured in this way, the transformer 27
The % impedance voltage between the primary and secondary is set in advance to a high impedance of 40% to nearly 100%, taking into account the lagging reactive power generation capacity, and also in response to the generation status of leading reactive power in the power system. By controlling the phase angle of the on/off operation of the thyrisk switch 11,
The lagging power generated based on the impedance voltage of the transformer 27 can be adjusted by wN, and as a result, the power system 1
It is possible to compensate for the phase advancing reactive power on the 0 side. In determining the voltage and current of the secondary winding 29, an economical design is adopted that takes into consideration the decorative capacitance of the thyristor elements constituting the thyristor switch 11 and the number of them in series, as in the case of the conventional structure shown in FIG. be.

The embodiment of FIG. 3 is characterized in that the transformer 27 is a three-winding transformer having a tertiary winding 30 connected in delta. In a device configured in this way,
Among the harmonics generated due to the on/off control of the Cyrisk switch, the third harmonic flows through the delta-connected tertiary winding and is used in the power system! The primary winding 2 connected to the ultra-high voltage power system can be prevented from flowing to the +1110 side.
8 can be star connected. Therefore, it can be expected that the burden voltage of each phase winding of the secondary winding will be reduced, and that the neutral point side will be effectively grounded, resulting in reduced insulation. Therefore, the insulation of the secondary winding will be simplified, and the transformer 27 will be It can be made smaller and lighter. In addition, by configuring the tertiary winding 30 to be used as a winding exclusively for the harmonic filter, the tertiary winding 30
By determining the voltage in consideration of the economic efficiency of the reactor 26 and the capacitor 26, the harmonic filter can be constructed smaller and at a lower cost than the conventional construction. Also,
Because the separated impedance of the tertiary winding (which can be seen from the equivalent circuit of a three-winding transformer) can be used to configure the harmonic filter 24 or as part of the accelerator 25, the reactor 2
There is an advantage that the capacity of 5 can be reduced. Also, the component that constitutes the harmonic filter 24 connected to the tertiary winding 30? Densa 2
6 can also be used as a phase advance capacitor if necessary.

As described above, in the embodiment shown in FIG. 3, the delayed phase power is generated by using the leakage impedance between the primary and secondary windings, and the separation impedance of the tertiary winding is generated by using a part of the inductance of the harmonic filter. The configuration is such that it is easily affected by the distribution of leakage impedance between the windings of the transformer. As for the distribution of leakage impedance, the leakage impedance between the -order secondary winding is set to a high impedance commensurate with the slow phase capacitance, and the leakage impedance between the primary, secondary and tertiary windings is increased to a certain extent. This leakage impedance can be used for a filter that absorbs harmonics mainly generated on the side, and the lagging phase capacitance generated between the -th order secondary winding and the phase leading capacitance on the secondary winding side are combined. This provides the advantage of preventing the generated delayed phase reactive power from decreasing.

〔Effect of the invention〕

As described above, the present invention configures a transformer that generates delayed phase reactive power as a three-winding transformer with a delta-connected tertiary winding, and slows the leakage impedance between the negative and secondary windings. In addition to providing a high impedance commensurate with the phase capacity, a si-risk switch is installed on the secondary winding side to control the delayed phase power, and the delta-connected tertiary winding is used as a dedicated winding for harmonic filters. accomplished. As a result, first, the third harmonic is absorbed by the tertiary winding, and harmonics of other orders are absorbed by the harmonic filter, thereby preventing harmonic current from flowing to the tortoise gun side. In addition, the voltage of the tertiary winding can be set to the optimal value considering the insulation cost of the harmonic filter.
Compared to conventional systems that directly connect a harmonic filter to the power system, the harmonic filter can be made smaller and cheaper. Furthermore, since the separated impedance of the tertiary winding can be used as part of the inductance of the harmonic filter, it is possible to reduce the burden of the harmonic filter.

Furthermore, it is now possible to star-connect the secondary windings, and if the device is directly connected to an ultra-high voltage power transmission system that generates phase-advanced reactive power, insulation on each phase winding and neutral point side should be This can contribute to the miniaturization of transformers. Therefore, even when directly connected to a power system that generates phase-advanced reactive power, it is possible to provide a stationary non-active power adjustment device that does not increase the size of the device or cause economic disadvantage.

[Brief explanation of the drawing]

Fig. 1 is a connection diagram of a conventional reactive power adjustment device, Fig. 2 is a connection diagram of an improved conventional reactive power adjustment device, and Fig. 3 is a thermodynamic power adjustment diagram showing an embodiment of the present invention. It is a connection diagram of a device. 111--Thyristor switch, 1.21--Synchronized reactive power flli adjustment circuit, 4.24--Harmonic filter, 5゜25--Reactor, 6.26--Capacitor, 7--・Leakage transformer, 27...Three-phase three@gland transformer 1.8.28...-Secondary winding, 9.29...Secondary winding, 30...Tertiary winding, 1oI20 -...Electric power system. Figure 1 Figure 2 Figure 3

Claims (1)

[Claims] Engineering) The secondary winding of a leakage transformer connected to a three-phase power system that generates phase-advanced reactive power is controlled by an anti-parallel connection thyrisk switch provided on the secondary winding side of the transformer. #i! In a device that generates and controls slow-phase reactive power by turning on and off current, the transformer has a delta-connected tertiary winding, and a series resonant circuit connected to this tertiary winding or an accelerator and a condenser. - A stationary invalid force wIN adjustment device, characterized in that it is equipped with a humming harmonic filter. 2. In the device according to claim 1, the primary winding of the transformer is star-connected, and the impedance voltage between it and the secondary winding exceeds 40% of the rated voltage of the secondary winding. % or less.