Solar photovoltaic charge control device

Abstract

The invention discloses a solar photovoltaic charge control device. A PWM signal drive component (6) comprises an RC low pass filter (61), a PWM chip (62) and a logic gate circuit (63) which are connected in series, and is used for providing drive signals of an auxiliary switch (31), a main switch (32) and a synchronous rectification switch (33) to a DC-DC conversion component (3) in time sequence according to PWM duty ratio signals of a microprocessor (5). The DC-DC conversion component (3) is composed of the main switch (32) with the two ends being connected with first resonance capacitors (C1) in parallel, the synchronous rectification switch (33) with the two ends being connected with second resonance capacitors (C2) in parallel, the auxiliary switch (31), a resonance inductor (Lr) and a filter inductor (Lf). The DC-DC conversion component (3) is used for sequentially enabling the synchronous rectification switch (33) to be turned off with zero current, the main switch (32) to be turned on with zero voltage and then turned off with quasi zero voltage according to set time of duty ratio, and the synchronous rectification switch (33) to be turned on with zero voltage and drop voltage of the synchronous rectification switch (33) at a steady state by not higher than 0.1 V. The solar photovoltaic charge control device can be widely applied to high-power photovoltaic electricity generation systems.

Description

technical field [0001] The invention relates to a charging control device, in particular to a solar photovoltaic charging control device. Background technique [0002] Photovoltaic charging power generation is a technology that uses the photovoltaic effect in the solar cell array to convert light energy into electrical energy and store it in the battery for load use. When this technology is implemented, a photovoltaic charge controller needs to be configured between the solar cell array and the storage battery, such as in "Design of a Photovoltaic Charge Controller with MPPT Control" ("Journal of Electrical and Electronic Teaching", December 2011, Volume 33, No. 6 issue, pages 61-64) disclosed in a photovoltaic power generation charging control system. The system is mainly composed of a solar cell array, a battery and a controller. The controller is mainly composed of a DC-DC converter, a charging current and battery voltage detector, a PWM (pulse width modulation) driver a...

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Problems solved by technology

However, although this kind of photovoltaic charge controller can detect the charging voltage and charging current of the battery, in the case of sufficient light intensity, according to the characteristics of the battery being charged, it adopts the commonly used three-stage charging control of constant current, constant voltage and floating charge. The method completes the intelligent control of the battery, and automatically switches to the MPPT control state under the condition of insufficient light intensity, so that the photovoltaic cell has the maximum power output by using the disturbance observation control strategy, thereby improving the power generation efficiency of the photovoltaic cell, but There are also disadvantages at the same time. First of all, it is only suitable for small and low-power photovoltaic power generation systems. For high-power photovoltaic power generation systems, especially involving photovoltaic power generation systems that require large current output, the power loss of the diodes will be too high. The high efficiency of the system leads to low efficiency; secondly, because the P-channel power MOS tube is not in a zero-voltage state when it is turned on, it has a large inrush current, especially for high-power photovoltaic power generation systems. early damage

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