(1) Product overview

　　The MDPA product is a comprehensive solution suitable for low-voltage power distribution networks. It uses advanced power electronic technology to adjust the three-phase load imbalance. It can also detect the reactive current in the load in real time, and use IGBT to invert The opposite compensation current ensures that the current fed from the grid is an active balance current, reducing grid pollution and realizing "green" power supply.

　　A) Working principle

　　MDPA detects the load current in real time through an external current transformer, decomposes the detected current in positive and negative sequence, and extracts unbalanced current and reactive current. These signals enter the DSP for calculation and processing to obtain the comprehensive compensation current that MDPA needs to output. Then a PWM signal is generated to drive the IGBT to act, and the load current is redistributed to the grid side while realizing reactive power compensation. The core function of the product is that it can operate at a speed 500 times faster than the current conversion speed to be compensated, and realize the real-time adjustment of impedance. The working principle diagram of MDPA is as follows:

　　B) Main functions of MDPA

　　1) Adjust three-phase unbalanced current, three-phase unbalance compensation function

　　2) Compensate a part of the reactive current of the three-phase distribution network to improve the power factor.

　　C) MDPA technical characteristics:

　　1) Powerful, one-stop solution for power quality

　　Ø Three-phase unbalance compensation function

　　Ø Voltage compensation function

　　Ø Dynamic real-time tracking of system reactive power changes, no range compensation system reactive power, no over-compensation or under-compensation

　　Ø Two-way compensation system reactive power

　　Ø Harmonic filter function (option)

　　Ø Support remote data transmission function (option)

　　2) Excellent compensation effect

　　Ø MDPA is an active compensation device, which uses modern power electronic devices IGBT to form a current source device, which avoids the resonance phenomenon caused by traditional capacitor components in mechanism, and is more stable and safe.

　　Ø Adopt high-speed DSP+FPGA fully digital control system, fast response to load changes, automatic real-time adjustment, response time less than 15 milliseconds.

　　3) Using a three-level topology, compared with a traditional two-level inverter, the three-level output voltage ladder waveform makes the compensation current closer to a sine wave;

　　4) MDPA has complete protection functions: overvoltage protection, undervoltage protection, overcurrent protection, overheating protection, short circuit protection, etc.

　　5) Modular design, easy to expand, easy to transport, easy to maintain, and the workload of engineering design and installation is small.

　　6) Low noise design

　　7) Small size and light weight.

　　D) Product application

　　The company's MDPA products have been applied in many power supply companies in cities and towns, with good results. It can effectively solve the problem of low voltage qualification rate of outdoor pole transformer low-voltage 400V system, effectively solve the problem of client current imbalance, and optimize the operating conditions of low-voltage distribution transformers; DPA can also compensate for reactive power and improve power factor.

　　　　(2) Product model

　　　　(3) Product parameters