CN203056590U - Dynamic reactive power compensation device for traction power supply system - Google Patents

Abstract

The utility model provides a dynamic reactive power compensation device for a tractive power supply system. The dynamic reactive power compensation device for the tractive power supply system is used for realizing dynamic reactive power balance of the tractive power supply system. The dynamic reactive power compensation device for the tractive power supply system is hooked on a 27.5kV bus in a station directly through an indoor vacuum circuit breaker. A manual isolating switch is arranged between the dynamic reactive power compensation device for the tractive power supply system and the vacuum circuit breaker. A parallel reactor is arranged in a self-coupling voltage-adjusting transformer, so that an adjustable parallel reactor branch circuit is formed. Two on-load voltage-adjusting switches are arranged in the self-coupling voltage-adjusting transformer. A parallel capacitor compensation return circuit is composed of a parallel capacitor and a reactor. A voltage transformer is connected to the capacitor branch circuit in parallel, so that a differential voltage protection return circuit of the parallel capacitor branch circuit is formed. Two current transformers are connected to two sides of the parallel capacitor branch circuit in series, so that a differential current protection return circuit is formed. Two lightning arresters are connected to two sides of the self-coupling voltage-adjusting transformer in parallel, so that an over-voltage protection return circuit is formed.

Description

Dynamic reactive power compensation device for traction power supply system

technical field

The utility model relates to an electrified railway traction power supply system, in particular to a dynamic reactive power compensation device for the traction power supply system.

Background technique

For electrified railways in mountainous areas, the slope of the line is usually relatively large, and the traction load fluctuates violently. Especially in the initial stage of opening, there is a large gap between the actual traffic volume and the designed traffic volume, resulting in a small current in the power supply arm and a very low utilization rate of the traction transformer capacity. The traction power supply system adopts the traditional fixed reactive power compensation device, and the situation of reactive power under-compensation or over-compensation in the traction power supply system is unavoidable.

In order to solve the power factor problem, the dynamic reactive power compensation device has been gradually promoted and applied in the traction power supply system. Dynamic reactive power compensation system (SAVDC), reactive power generator (SVG), etc.

After the proof and test of the actual operation on site, there are certain problems and defects in various methods. Thyristor-controlled reactor (TCR) mode is due to the drastic changes in railway traction load and high harmonic content, etc., the operating conditions of thyristors are relatively harsh, and damage often occurs, resulting in the system not operating normally, and the device has loss at light load and no load Larger problems; due to the dynamic adjustment of the magnetic saturation of the reactor in the controllable magnetic saturation reactor mode, the heat and noise are relatively large, and the device has a large loss when the device is light-loaded and no-load; there is a step-by-step voltage regulation high-voltage dynamic reactive In the compensation system (SAVDC) mode, since the controllable parallel capacitor branch cannot work in the zero voltage state, capacitive reactive power will be sent back to the grid under no-load and light load conditions. For lines with light loads, the power factor cannot meet the assessment requirements of the power department. ; The reactive power generator (SVG) system is relatively complex, with low reliability and high price, and lacks relatively mature operating experience in electrified railways.

Utility model content

The technical problem to be solved by the utility model is to provide a dynamic reactive power compensation device for the traction power supply system, so as to realize the dynamic reactive power balance of the traction power supply system.

The technical solution adopted by the utility model to solve its technical problems is as follows:

The dynamic reactive power compensation device of the traction power supply system of the utility model is characterized in that: the device is directly connected to the 27.5kV bus in the institute through the indoor vacuum circuit breaker, and a manual isolating switch is set between the vacuum circuit breaker; self-coupling voltage regulation The transformer is equipped with a shunt reactor to form an adjustable shunt reactor branch; the first on-load tap changer and the second on-load tap changer are set in the auto-coupling tap changer; the shunt capacitor and the reactor constitute the shunt capacitor compensation circuit; the voltage transformer is connected in parallel on the capacitor branch to form a differential pressure protection circuit for the parallel capacitor branch; the first current transformer and the second current transformer are connected in series on both sides of the parallel capacitor branch to form a differential current protection circuit; A lightning arrester and a second lightning arrester are connected in parallel on both sides of the auto-transformer to form an overvoltage protection circuit.

The beneficial effect of the utility model is that a special auto-coupling voltage-regulating transformer is adopted, and two sets of on-load tap-changers are set, one set controls the reactive power output of the shunt capacitor, and the other set controls the reactive power output of the shunt reactor. Through the dynamic coordination and cooperation of the inductor and capacitor branches, the dynamic reactive power balance of the traction power supply system is realized; since the inductor branch is mainly used to offset the excessive capacitive reactive power at no-load or light load, the capacity Therefore, the reactor is placed in the oil tank of the autotransformer, and the transformer oil is used to solve the insulation and heat dissipation problems of the reactor to achieve a compact design.

Description of drawings

This manual includes the following two drawings:

Fig. 1 is a schematic structural view of the dynamic reactive power compensation device of the utility model for traction power supply system;

Fig. 2 is a schematic diagram of the internal wiring of the auto-coupling voltage regulating transformer in the dynamic reactive power compensation device used in the traction power supply system of the present invention.

The figure shows the names of the components and the corresponding marks: 27.5kV bus α in the institute, indoor vacuum circuit breaker 1QF, manual isolating switch 1QS, autotransformer 1TY, shunt reactor DK, first on-load tap changer K1, The second on-load tap changer K2, the shunt capacitor 1C, the reactor 1L, the voltage transformer 1TV, the first current transformer 2TA, the second current transformer 4TA, the first lightning arrester 1F, and the second lightning arrester 2F.

Detailed ways

Below in conjunction with accompanying drawing and embodiment the utility model is further described.

Referring to Fig. 1 and Fig. 2, the dynamic reactive power compensation device of the traction power supply system of the present utility model is characterized in that the device is directly connected to the 27.5kV bus α in the institute through the indoor vacuum circuit breaker 1QF, and is connected to the vacuum circuit breaker. Set the manual isolating switch 1QS; the autotransformer 1TY is equipped with a shunt reactor DK to form an adjustable shunt reactor branch; the first on-load tap changer K1 and the second on-load tap changer K2 are set in the Inside voltage transformer 1TY; Parallel capacitor 1C and reactor 1L constitute a parallel capacitor compensation circuit; Voltage transformer 1TV is connected in parallel to the capacitor branch to form a differential pressure protection circuit for the parallel capacitor branch; the first current transformer 2TA, the second current The transformer 4TA is connected in series on both sides of the parallel capacitor branch to form a differential current protection circuit; the first lightning arrester 1F and the second lightning arrester 2F are connected in parallel to both sides of the autotransformer 1TY to form an overvoltage protection circuit. The parallel capacitor 1C usually adopts 4 series N-parallel type capacitors.

The utility model utilizes the characteristics of the traditional step-regulated high-voltage dynamic reactive power compensation system (SAVDC) device, which is reliable in operation, low in price, and low in energy consumption, and improves on the basis of it. The self-coupling voltage regulating transformer A set of on-load tap changer is added, and a shunt reactor is added at the same time to form an adjustable shunt reactor branch. When there is no load or light load, the output of the adjustable shunt reactor inductive reactive power is adjusted to supplement the overvoltage. A large amount of capacitive reactive power ensures that the power factor meets the assessment requirements of the power department.

The utility model is a dynamic reactive power compensation device used in a traction power supply system. The device is directly connected to the 27.5kV busbar in the institute through an indoor vacuum circuit breaker. According to the reactive power change of the power grid system, the inductance and capacitance branches are dynamically adjusted. working voltage, adjust the inductive and capacitive reactive power output by the two branches, and realize dynamic reactive power compensation.

The device adopts on-load voltage regulating autotransformer, capacitor, reactor and other equipment with mature technology, which is stable and reliable in operation and low in price. Under normal load conditions, only the capacitor branch outputs capacitive reactive power to compensate the inductive reactive power of the traction load, and the reactor branch basically does not output inductive reactive power; under no-load or light-load conditions, the capacitor branch works at The lower position, the output of lower capacitive reactive power, the reactor branch output lower inductive reactive power, offset the capacitive reactive power output of the capacitive branch circuit, thus ensuring the balance of reactive power under various working conditions , At the same time, it also ensures the lower loss of the device under various working conditions. The device adopts a specially designed auto-coupling voltage-regulating transformer. The auto-coupling voltage-regulating transformer adopts the on-load voltage regulation mode, and two sets of on-load voltage-regulating tap-changers are set; one set of on-load voltage-regulating tap-changers controls the reactive power of parallel capacitors. For power output, the shunt capacitor is mainly used to compensate the inductive reactive power of the locomotive load; another set of on-load tap changer controls the reactive power output of the shunt reactor, which is mainly used to offset the no-load or light-load Excessive capacitive reactive power. The high-voltage reactive power compensation automatic control device composed of a computer collects the voltage, current and power factor of the power grid in real time, analyzes the change trend of the load, system reactive power, system harmonic content, voltage fluctuation, etc., and uses fuzzy control technology to adjust The on-load tap-changer realizes dynamic optimization compensation and achieves the purpose of automatic tracking and adjustment of reactive power compensation capacity along with system load reactive capacity.

The above is just to illustrate some principles of the utility model for the dynamic reactive power compensation device of the traction power supply system, not to limit the utility model to the specific structure and scope of application shown and described, so any All corresponding modifications and equivalents that may be utilized belong to the patent scope of the utility model application.

Claims (2)

1. The dynamic reactive power compensation device of the traction power supply system is characterized in that the device is directly connected to the 27.5kV busbar (α) in the institute through the indoor vacuum circuit breaker (1QF), and a manual isolating switch ( 1QS); the autotransformer (1TY) is equipped with a shunt reactor (DK) to form an adjustable shunt reactor branch; the first on-load tap changer (K1) and the second on-load tap changer (K2) It is installed in the auto-coupling voltage-regulating transformer (1TY); the parallel capacitance compensation circuit is formed by the parallel capacitor (1C) and the reactor (1L); the voltage transformer (1TV) is connected in parallel on the capacitor branch to form the differential pressure of the parallel capacitor branch Protection circuit; the first current transformer (2TA) and the second current transformer (4TA) are connected in series on both sides of the parallel capacitor branch to form a differential current protection circuit; the first arrester (1F) and the second arrester (2F) are connected in parallel On both sides of the autotransformer (1TY), an overvoltage protection circuit is formed. 2. The dynamic reactive power compensation device of the traction power supply system according to claim 1, characterized in that: the parallel capacitor (1C) adopts 4 series N-parallel type capacitors.

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