CN204615392U - Intelligent Distribution Transformer - Google Patents

Abstract

The utility model discloses a kind of Intelligent distribution transformer, it comprises a main transformer and a series transformer; Main transformer comprises primary coil I and the first secondary coil I, and series transformer comprises second subprime coil I, primary coil II and secondary coil II, and primary coil II is coupled with secondary coil II; Wherein: the first secondary coil I is connected secondary coil II, and secondary coil II bypass in parallel, bypass arranges bypass switch; Second subprime coil I series primary coils II, a compensation condenser of also connecting therebetween; Second subprime coil I and primary coil I are coupled as the power supply of series transformer; Second subprime coil I classification series voltage-regulating switch, in parallel between each tap changer.Can realize user side voltage automatically keeps output voltage stabilization within ± 5% in the excursion of-20%-0, power factor >=0.9.

Description

Intelligent Distribution Transformer

technical field

The utility model relates to an intelligent power distribution transformer mainly used for solving the problem of low voltage of terminal power distribution users.

Background technique

For terminal power distribution users with long-distance power transmission and large power supply radius, the problem of low voltage is very prominent. In the peak of power consumption, sometimes the voltage drops by more than 20%, and the voltage is relatively high at light loads. It is difficult to solve the problem of unqualified voltage quality with ordinary distribution transformers.

The low voltage problem is mainly due to the long transmission line and high line impedance. When the load current is large, the voltage drop of the line increases, and when the load current is small, the voltage drop decreases, resulting in a large fluctuation range of the terminal voltage. Existing transformers can only achieve qualitative transformation, but cannot achieve automatic tracking compensation.

Utility model content

The technical problem to be solved by the utility model is to provide an intelligent distribution transformer with automatic voltage regulation and compensation functions, which can effectively adjust the voltage at the end of a 10kV line.

In order to solve the above technical problems, the technical solution adopted by the utility model is: an intelligent distribution transformer, which includes a main transformer and a series transformer; the main transformer includes a primary coil I and a first secondary coil I, and the series transformer includes a first Secondary coil Ⅰ, primary coil Ⅱ and secondary coil Ⅱ, primary coil Ⅱ and secondary coil Ⅱ are coupled; where: the first secondary coil Ⅰ is connected in series with secondary coil Ⅱ, and secondary coil Ⅱ is connected in parallel with a bypass, and the bypass is set A bypass switch; the second secondary coil Ⅰ is connected in series with the primary coil Ⅱ, and a compensation capacitor is also connected in series; the second secondary coil Ⅰ is coupled with the primary coil Ⅰ as the power supply of the series transformer; The pressure regulating switches are connected in series on the circuit, and the pressure regulating switches are connected in parallel.

Optimally, the second secondary coil I is divided into four-stage series voltage-regulating coils, and the four-stage series-connected voltage-regulating coils with turns from less to more are respectively provided with voltage-regulating switches K1, K2, K3, and K4 in series.

The intelligent power distribution transformer of the utility model uses series capacitors to offset the influence of line inductance in long-distance power transmission lines. Since the series capacitor and the line inductance are connected in series, the current is the same, the voltage of the capacitor lags the current by 90 degrees, and the voltage of the inductor leads the current by 90 degrees, so the capacitor voltage and the inductor voltage are exactly opposite and can cancel each other out. When the capacitive reactance of the series capacitor is equal to the inductive reactance of the line inductance, the voltage of the line inductance and the capacitor voltage are completely offset, so the power transmission capacity of the grid is greatly improved, and the voltage stability is also greatly improved. It adopts the method of connecting the series transformer to the series capacitor to reduce the line impedance to reduce the voltage fluctuation. When the load peak voltage drop is too large, it further uses the autotransformer to automatically adjust the voltage to achieve voltage stabilization. It has automatic voltage adjustment and compensation functions. It is mainly aimed at the problem of low voltage at the end of the 10kV line. The intelligent distribution transformer adopts the voltage regulating transformer connected in series from the low-voltage side, combined with the series-parallel comprehensive reactive power compensation technology, and realizes the stable voltage output with the comprehensive automatic control strategy of voltage priority and reactive power balance. Comprehensive automatic control strategy to achieve stable voltage output and reactive power to reach the target. It can automatically keep the output voltage stable within ±5% within the range of -20%-0 of the user terminal voltage, and the power factor is ≥0.9.

Description of drawings

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

Fig. 1 is a schematic diagram of the circuit connection of an embodiment of the intelligent distribution transformer of the present invention.

Detailed ways

Example 1

As shown in Figure 1, the intelligent distribution transformer of this embodiment includes a main transformer and a series transformer; the main transformer includes a primary coil I1 and a first secondary coil I2, and the series transformer includes a second secondary coil I5, a primary Coil II4 and secondary coil II3, primary coil II4 and secondary coil II3 are coupled; wherein: the first secondary coil I2 is connected in series with the secondary coil II3, the secondary coil II3 is connected in parallel with a bypass, and a bypass switch 6 is arranged on the bypass; The secondary coil I5 is connected in series with the primary coil II4, and a compensating capacitor 7 is also connected in series; the second secondary coil I5 is coupled with the primary coil I1 as the power supply of the series transformer; A plurality of four-stage series-connected voltage-regulating coils are respectively provided with voltage-regulating switches K1, K2, K3, and K4 in series, and the above-mentioned voltage-regulating switches are connected in parallel.

The intelligent distribution transformer of this embodiment adopts the method of connecting the series transformer to the series capacitor 7 to reduce the line impedance to reduce the voltage fluctuation. When the load peak voltage drop is too large, the automatic voltage regulation of the autotransformer is further used to realize voltage stabilization. With automatic pressure regulation and compensation function. Mainly for the low voltage at the end of the 10kV line.

When the bypass switch 6 is closed, the intelligent distribution transformer has no voltage regulation function and can only be used as an ordinary transformer, the output voltage is increased by 5%, and the voltage regulation coil of the main transformer adjusts the terminal voltage of the compensation capacitor through the electronic switch to realize automatic reactive power compensation. When the bypass switch 6 is turned on, the voltage regulating coil changes the secondary voltage applied to the series transformer through the electronic switch, thereby realizing on-load voltage regulation. At this time, the current flowing through the capacitor is used for the ampere-turn balance principle of the series transformer and the load The current is proportional, and the capacitor plays the role of series compensation, which can realize the natural tracking of the reactive power output and the load, and at the same time, the capacitor voltage superimposed on the series transformer also plays the role of boosting the voltage. When K1 is closed and K2, K3, and K4 are opened, the voltage is adjusted by 6%, and the output voltage of the intelligent distribution transformer is increased by 11%; when K2 is closed, and K1, K3, and KD4 are opened, the voltage is adjusted by 12%, and the output voltage of the intelligent distribution transformer Increased by 17%. When K3 is closed and K1, K2, and K4 are open, the voltage regulation is 16%, and the output voltage of the intelligent distribution transformer is increased by 23%. When K4 is closed, and K1, K2, and K3 are open, the voltage regulation is 24%, and the output voltage of the intelligent distribution transformer is Increased by 29%.

Claims (2)

1. An intelligent distribution transformer, characterized in that: it includes a main transformer and a series transformer; the main transformer includes a primary coil I and a first secondary coil I, and the series transformer includes a second secondary coil I and a primary coil II And the secondary coil II, the primary coil II is coupled with the secondary coil II; wherein: the first secondary coil I is connected in series with the secondary coil II, the secondary coil II is connected in parallel with a bypass, and a bypass switch is set on the bypass; the second secondary coil Ⅰ is connected in series with the primary coil Ⅱ, and a compensating capacitor is also connected in series; the second secondary coil Ⅰ is coupled with the primary coil Ⅰ as the power supply of the series transformer; The pressure switches are connected in parallel. 2. The intelligent distribution transformer according to claim 1, characterized in that: the second secondary coil I is divided into four-stage series voltage-regulating coils, and the four-stage series-connected voltage-regulating coils with turns from few to many correspond to The pressure regulating switches K1, K2, K3, K4 are arranged in series.