JPS6225836A - Solar cell power source unit - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] Industrial Application Public Expenses The present invention relates to a power supply device consisting of a solar cell and a storage battery, and more specifically to a circuit that reliably prevents overcharging and undercharging of a storage battery by a solar cell. It is.

Conventional technology and the intervening point In an excitation solar cell power supply device, a storage battery is charged by a solar cell that converts irradiated light energy into electrical energy, and power is supplied to a load, while the storage battery is turned off when no light energy is irradiated. A type of uninterruptible power supply that is configured to supply power to a load through discharge, and is often used in wireless relay stations where stable and reliable power sources such as commercial power sources are difficult to obtain. However, such solar battery power supply devices have the capacity to supply uninterrupted power to the load regardless of changes in weather conditions, so if the weather continues to be good, the storage battery may become overloaded. Sometimes it got charged.

As a solution to the above drawbacks, JP-A-58-10
Publication No. 3881 describes a structure as shown in FIG. That is, in FIG. 2, the electrical energy converted from the light energy irradiated onto the solar cell 1 charges the storage battery 3 and is supplied to the load 4 via the backflow blocking diode 2. Furthermore, the storage battery 3 is equipped with a voltage detector 5 and a specific gravity detector 9, and the output thereof is configured to operate an overcharge prevention circuit 6 connected between the output terminals of the solar cell 1. This overcharge prevention circuit 6
A thyristor 7 is provided, and relay contacts 8, 10 and a resistor 11 are connected between its gate and anode. In the conventional device with such a configuration, the charging voltage of the storage battery 3 is monitored by the voltage detector 5, the electrolyte specific gravity of the storage battery 3 is monitored by the specific gravity detector 9, and when both reach the set value, the relay contact 8 is , 10 are closed and the thyristor 7
is turned on to prevent the output of the solar cell 1 from being bypassed and overcharging the storage battery 3.

However, even with the same charging current, the charging voltage of the storage battery 3 rises at a smaller rate when the temperature of the storage battery 3 is high than when it is low, and 4) The device itself is subject to temperature differences of up to 40°C. Since the batteries are sometimes installed at unmanned wireless relay stations in the mountains, they can sometimes be overcharged or undercharged depending on the season. For this reason, it is known to configure the overcharge prevention circuit 6 so that the operating point can change depending on the ambient temperature, but since changes in the ambient temperature and changes in the temperature of the storage battery 3 do not necessarily coincide, It was not possible to reliably prevent charging or insufficient charging.

OBJECTS OF THE INVENTION The present invention solves the above-mentioned drawbacks, and aims to provide a highly reliable solar battery power supply device by preventing overcharging and undercharging of storage batteries due to temperature differences.

Structure of the Invention In the solar battery power supply device of the present invention, a temperature detector for monitoring the electrolyte temperature is installed in parallel with a specific gravity detector for monitoring the electrolyte specific gravity of one storage battery, and the charging voltage of the storage battery is detected by the temperature detector. The detected value of the voltage detector is corrected for the electrolyte temperature, and the overcharge prevention circuit is activated when the corrected detected value and the electrolyte specific gravity reach a set value or when the electrolyte temperature exceeds a certain value. It is configured to operate.

EXAMPLES The present invention will be explained below using examples. FIG. 1 is a block diagram of a solar cell source device according to the present invention.

In FIG. 1, the same numbers are used for parts having the same functions as in FIG. 2. There are 12 temperature detectors according to the present invention, one output of which is input to a voltage detector 5 that detects the charging voltage of the storage battery, and the detected value is corrected for the electrolyte temperature, and the other output is a relay. The overcharge prevention circuit is configured to operate independently as a signal for closing the contact 13 when the electrolyte temperature rises abnormally.

When light energy is irradiated to the solar cell 1 source device of the present invention having W composition as described above, the electrical energy converted by the solar cell 1 charges the storage battery 3 via the backflow blocking diode 2. Power is supplied to load 4. If the light energy is insufficient, the specific gravity detector 9 and voltage detection circuit 5 will not operate. When sufficient light energy is supplied and charging of the storage battery 5 progresses, both the charging voltage and the specific gravity of the electrolyte increase, and the temperature of the storage battery 3 itself also increases regardless of changes in the ambient temperature. This is because water electrolysis occurs in the electrolytic solution as charging progresses, raising the temperature of the electrolytic solution. The liquid temperature can be detected accurately, and the detected value of the voltage detector 5 is corrected with respect to the electrolyte temperature based on one detected output. When the corrected detection value of the voltage detector 5 reaches the set value, the relay contact 8 is first closed, and when the electrolyte specific gravity of the storage battery 3 detected by the specific gravity detector 9 reaches the set value, the relay contact 8 is closed. Contact 10 is closed. When relay contacts 8 and 10 are both closed in this way, thyristor 7 is turned on, the output of solar cell 1 is bypassed, and overcharging of storage battery 5 is prevented. On the other hand, when the electrolyte temperature of the storage battery 6 abnormally rises for some reason (for example, when it exceeds 50°C), the relay contact 13 is closed by the other output of the temperature detector 12, and overcharging is prevented independently. It operates the circuit, prevents damage to the storage battery, and improves the reliability of the solar battery power supply.

This overcharge prevention circuit 6 is turned off when the output of the solar cell 1 is no longer transmitted or when the storage battery 3 discharges to the load and the voltage drops, the current of the thyristor 7 decreases below the holding current and turns off. It will be released.

Effects of the Invention As detailed in the embodiments, the solar cell power supply device of the present invention can accurately detect the electrolyte temperature and electrolyte specific gravity of the storage battery, and correct the detected value of the voltage detector with respect to the electrolyte temperature. Therefore, it is possible to reliably prevent overcharging and undercharging of the storage battery due to temperature differences, etc., and is extremely reliable.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of the solar cell power supply device of the present invention, tJ
The z diagram is 1 of a conventional solar battery power supply device! It's the footer.

Claims (1)

[Claims] In a solar battery power supply device configured such that a storage battery is charged by a solar battery and power is supplied to a load, a temperature detector that monitors the temperature of the electrolyte is added to a specific gravity detector that monitors the specific gravity of the electrolyte of the storage battery. When the detected value of the voltage detector which is installed in parallel and detects the charging voltage of the storage battery using the temperature sensor is corrected for the electrolyte temperature, and this corrected detected value and the electrolyte specific gravity reach a set value. Alternatively, a solar cell power supply device is characterized in that charging of a storage battery by a solar cell is stopped when the electrolyte temperature exceeds a certain value.