Distribution Transformer Integrated Cascaded Static Compensator

Abstract

The invention discloses a distribution transformer integrated cascaded static compensator, which includes a distribution transformer, a cascaded static compensation module, an output filter and a control platform, and is set at the center of each phase winding on the high voltage side of the distribution transformer The connection tap is used as the injection point of the compensation current, and the connection tap is connected to the AC output terminal of the cascaded static compensation module through the output filter, and the control input terminal of the cascaded static compensation module is connected to the control platform, and the control platform is used to collect distribution transformers Based on the voltage and current information at the high and low voltage sides and the connection taps, the tracking command current signal is generated based on the information, and the output of the cascaded static compensation module is controlled by the tracking command current signal to achieve compensation. The invention integrates the cascaded multi-level structure and the distribution transformer, increases the capacity of the static compensator of the distribution network, and improves the power quality of the distribution network.

Description

technical field [0001] The invention relates to the field of reactive power compensation in power systems, in particular to an integrated static var compensator integrating a distribution transformer and a cascaded chained STATCOM (Static Synchronous Compensator). Background technique [0002] Traditional distribution network reactive power compensators (D-STATCOM) mostly use reactive power compensation directly on the load side, such as figure 1 As shown, due to the low level of access voltage and scattered installation, the compensation capacity is limited, and the utilization rate of the overall reactive power compensation capacity is not high; figure 2 The large-capacity centralized compensation on the high-voltage side of the distribution network system shown above faces the problem that the access point voltage is high, and the main circuit is usually unable or difficult to be directly connected to the system. [0003] In order to increase the reactive power compensa...

AI Technical Summary

Problems solved by technology

[0004] 1 A single switching device still bears a large switching stress, and the withstand voltage level of the full-control switching device is high. The access point of the static compensation device cannot be flexibly configured in a wide range, and the compensation capacity is limited;

[0005] 2. The output voltage waveform of the inverter has fewer levels and higher harmonic content, so a complex high-order LCL filter needs to be designed to realize output grid connection;

[0006] 3. The three phases are not independent, do not have the independent control capability of phase separation, and cannot overcome the influence of the three-phase unbalance of the power system;

[0007] 4 It is difficult to implement modularization, which is not conducive to expansion, and it is necessary to set up a resistance-capacitance absorption circuit

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