Energy-regeneration type converter power test system and method

Abstract

The invention discloses an energy-regeneration type converter power test system and method. The system comprises a power grid, an isolation transformer, a first smoothing reactor, a second smoothing reactor and a tested converter. The tested converter comprises a first PWM converter, a second PWM converter and a direct current bus capacitor, wherein the first PWM converter and the second PWM converter transmit active power under the buffer effect of a direct current bus capacitor. The first PWM converter imitates load characteristics of the system. The second PWM converter achieves system energy regeneration, unit power factor inversion is achieved by controlling the output currents of the second PWM converter and the voltages of the power grid to be identical in frequency and phase, and the active power balance between the input and the output of the tested converter is achieved by controlling the direct current voltages between the first PWM converter and the second PWM converter to be constant. The energy-regeneration type converter power test system and method can effectively ensure test quality, improve test efficiency, improve the equipment utilization rate, save equipment cost, save energy, reduce emission, simplify operation entry barriers and eradicate potential safety hazards.

Description

technical field [0001] The invention relates to an electrical test system and a method thereof, in particular to an energy-feedback type converter power assessment test system and a method thereof with a transformer as a load. Background technique [0002] A converter is a power control device that uses the on-off function of a power semiconductor device to convert a commercial frequency power supply into another frequency-adjustable (or fixed-frequency) power control device. It is a device that transforms the industrial frequency power supply (50Hz or 60Hz) into AC power supply of various frequencies to realize variable speed operation control of the motor or connect electric energy to the grid. Among them, the control circuit completes the control of the main circuit, the rectification circuit converts the alternating current into direct current, the direct current intermediate circuit smoothes and filters the output of the rectification circuit, and the inverter circuit i...

AI Technical Summary

Problems solved by technology

[0010] (1) The construction cost of the power supply system is high: high-power assessment will inevitably require a high-power power supply for power supply, and the construction cost of a high-power power supply system is very high. For example, an ordinary 2.5MVA power supply system will cost about 1.2 million yuan to construct about;

[0011] (2) Great interference to the power grid: Due to the full power assessment, the interference to the power grid is relatively large, so sometimes it is necessary to perform power management on the power grid, which also leads to an increase in additional costs, and the huge heat dissipation also causes the experimental system The construction cost puts forward higher requirements;

[0014] (1) The construction cost of the test system is high: high-power assessment will inevitably require high-power power supply for power supply, and high-power grid-connected feedback load system (including motors, generators, grid-connected converters, grid-connected transformers, etc.), The construction cost of the entire test system is very high. For example, a set of ordinary back-to-back motor-to-drag feedback 2.5MVA test system needs about 5 million yuan to build;

[0015] (2) Great interference to the power grid: due to the full power assessment, the interference to the power grid is relatively large. Carry out power management, which also leads to an increase in additional costs. If there is no absolute profit margin as support, it will bring a great economic burden to the enterprise;

[0016] (3) Poor versatility: different converters need to be configured with different dragging motor loads;

[0017] (4) Complex inspection and maintenance: complex systems will inevitably put forward higher requirements for inspection and maintenance

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