A control method for interlaced phase shifting of a photovoltaic inverter and a photovoltaic inverter

Abstract

The invention provides an interleaving phase-shift control method for a photovoltaic inverter and the photovoltaic inverter. Interleaving control on the control quality is realized; and an input current ripple amplitude value is reduced by prediction control and time compensation strategies in the control process, so that the design of an electro-magnetic interference (EMI) filter is simplified. Relatively low filter capacitance and boost inductance are permitted to be adopted by increase of the current ripple frequency, so that the size of the overall system is reduced; and the power density of the system is improved. The overall system is relatively uniform in thermal stress to obtain relatively high reliability; meanwhile, the thermal loss of the system can be reduced; and the service life of the overall system is prolonged.

Description

technical field [0001] The invention relates to a control method of a photovoltaic inverter and the inverter, in particular to a control method for interleaved phase shifting. Background technique [0002] Traditional fossil fuel energy with limited resources and serious pollution is decreasing day by day, so clean and renewable energy with unlimited resources has become the focus of attention. Among them, solar energy, as an emerging green energy, is being rapidly popularized and applied due to its advantages such as inexhaustibility, no pollution, and no limitation of geographical resources. According to the principle of photovoltaic effect, photovoltaic technology, which uses solar cells to directly convert sunlight energy into electrical energy, is a very important technology that can realize the transition of human beings to a sustainable global energy system. It is generally believed in the world that in the long-term energy strategy, solar photovoltaic power generati...

AI Technical Summary

Problems solved by technology

[0007] However, in practice, when the hardware circuit has been determined, it is necessary to realize the alternate phase-shift control through software. In software, the software phase-shift lag control strategy is generally used to realize it, such as figure 1 In the above, due to the software phase shift of 180°, it is necessary to add a timer in the program to configure the corresponding drive generation, and because one of the phases lags behind the control by 180°, there is a control phase shift

However, due to the use of phase shift lag control strategy, the system will have hysteresis, which will affect the stability and rapidity of the system. At the same time, due to the increase of the system timer, when the system resources are tight, this method cannot be used.

[0008] To sum up, in order to reduce the cost of hardware modification, it is necessary to use software to achieve phase shift 180° interleaved control. However, the software is currently widely used to lag 180° to achieve interleaved control, but it will increase system timer resources. Due to the use of hysteresis Control will affect the stability and rapidity of the system, and even cause problems such as system oscillation when it is bad

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