Medium-voltage series capacitor compensating device and transformer containing same

Abstract

The invention designs a medium-voltage series capacitor compensating device and a transformer containing same. Medium-voltage series capacitor compensation is achieved by connecting in series a capacitor bank with the ternary-side loop circuit of an electric furnace transformer and belongs to a kind of longitudinal capacitance compensation. The medium-voltage series capacitor compensating device comprises a voltage-regulating winding of a main transformer, a series transformer, a bidirectional change-over switch, and a capacitor element. The high-voltage winding of the series transformer is connected in series with the ternary-side loop circuit of the main transformer. The low-voltage winding of the series transformer is connected with the secondary winding of the main transformer. One end of the high-voltage winding is connected with one end of the bidirectional change-over switch. The other end of the high-voltage winding is connected with one end of the capacitor element. The other end of the capacitor element is connected with a sliding contact of the main transformer voltage-regulating winding. The other end of the bidirectional change-over switch comprises two contacts which are disposed on a positive fixing terminal and a negative fixing terminal of the voltage-regulating winding of the main transformer, respectively.

Description

technical field [0001] The present invention relates to an electric power compensation technology, more specifically, to a medium-voltage series capacitor compensation device of longitudinal reactive power compensation type and a transformer comprising the same. Background technique [0002] At present, enterprises such as ferroalloy and calcium carbide in my country are transforming to larger electric furnaces, and the power factor of large electric furnaces is relatively low. Due to the influence of the reactance and impedance of the electric furnace and the short network, the voltage loss of the furnace into the furnace is relatively large, so various reactive power compensation methods must be used to compensate. [0003] Horizontal compensation is a commonly used method, figure 1 It is a horizontal capacitance compensation method in which the capacitor bank is connected in parallel on the high voltage side of the electric furnace transformer. This compensation method ...

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Problems solved by technology

However, for the high-voltage winding connected to the compensation capacitor, in order to make the voltage change at both ends of the capacitor for adjusting the output voltage of the electric furnace transformer small, it is necessary to make the high-voltage winding adopt more than 15 levels of on-load voltage regulation, thereby increasing the investment.

[0006] Figure 4 It is a low-voltage direct compensation method, and its technical scheme is similar to image 3 , Figure 4 A large number of low-voltage non-standard capacitors are used in the scheme, which makes the investment large and the effective utilization rate of the capacitor is extremely low

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