A parallel control method for three-phase two-level inverters with isolation transformer

A technology of isolation transformer and control method, which is applied in the direction of single-network parallel feeding arrangement, etc., and can solve problems such as complex control algorithm and difficult implementation

CN102891500BActive Publication Date: 2014-10-29ZHUZHOU CSR TIMES ELECTRIC CO LTD
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Patent Information

Authority / Receiving Office
CN · China
Patent Type
Patents(China)
Current Assignee / Owner
Publication Date
2014-10-29

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Abstract

The invention discloses a parallel control method of a three-phase two-level inverter with isolation transformers. The parallel control method comprises the steps of: (1) connecting each auxiliary inverter with one isolation transformer, to be specific, modulating direct-current into alternating-current power with certain amplitude and frequency by the regulation of the auxiliary inverters, and then carrying out voltage reduction and filtering on the alternating-current by the isolation transformers to supply the power to alternating-current auxiliary loads on a motor train unit for use; (2) sampling the output line current of the auxiliary inverters and the liner voltage of secondary sides of the isolation transformers, calculating active power and passive power under the instantaneous output of the auxiliary inverters and carrying out filtering treatment; (3) generating given voltage amplitude signals and given frequency signals for current-sharing control of the auxiliary inverters by using a drooping characteristic algorithm; and (4) enabling the auxiliary inverters to output three-phase alternating-current power with certain voltage amplitude and frequency by means of voltage closed-loop control and frequency closed-loop control. The parallel control method has the advantages of simple principle, easiness for implementation, capabilities of improving antijamming capability of the system and greatly enhancing system reliability, and simultaneously reducing system hardware cost, and the like.
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Description

technical field

[0001] The invention mainly relates to the field of inverter parallel control design, in particular to a three-phase two-level inverter parallel control method with an isolation transformer. Background technique

[0002] Taking the auxiliary power supply system of the EMU as an example, as a part of the auxiliary power supply system of the EMU, the auxiliary inverter is mainly used to provide stable single-phase or three-phase AC power for air conditioning units, ventilation devices, air compressors, electric heaters, passenger rooms, etc. Used for AC auxiliary loads such as lighting. At present, the auxiliary inverters of most vehicles are single-unit operation, with large capacity and low reliability. Therefore, in order to improve the power supply reliability of the EMU auxiliary power supply system and provide redundancy for the auxiliary power supply, multiple auxiliary inverters can be operated in parallel.

[0003] The existing inverter parallel cont...

Examples

Embodiment Construction

[0045] The present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments.

[0046] Such as figure 1 As shown, the present invention has a three-phase two-level inverter parallel control method with an isolation transformer, and its steps are:

[0047] 1. Each auxiliary inverter is connected to an isolation transformer: through the adjustment of the auxiliary inverter, the direct current is modulated into an alternating current with a certain amplitude and frequency, and then is stepped down and filtered by the isolation transformer to supply the AC auxiliary load on the EMU. Use; the secondary side of the isolation transformer is connected to the busbar on the EMU through an auxiliary contactor.

[0048] see figure 2 , is a schematic diagram of forming a high-power auxiliary inverter parallel system for an EMU in a specific application example of the present invention. In this example, there are four auxi...