RU2258982C2 - Method for servicing nickel-hydrogen storage battery and storage battery implementing it - Google Patents

Abstract

FIELD: electrical engineering; servicing nickel-hydrogen batteries in off-line power systems.

SUBSTANCE: proposed nickel-hydrogen storage battery has n series-connected cells shorted out by means of bypass diodes in charge and discharge directions and by throwaway shorting devices. Proposed method includes conduction of charge-discharge cycles and shorting of defective cell by means of throwaway shorting device. Prior to shorting bypass diodes are checked for current carried by their circuits and check results are referred to in shorting the cell, heating elements of throwaway shorting device being inserted in bypass-diode circuits.

EFFECT: enhanced reliability and facilitated procedure of shorting defective cell.

4 cl, 2 dwg

Description

The present invention relates to the electrical industry and can be used in the operation of nickel-hydrogen storage batteries in autonomous satellite power supply systems.

There is a known method of operating a battery, which provides for “bypassing” a battery that has failed during operation by means of diode (bypass) circuits (see WIBillerbeck, WEBaker “The desing of reliable power systems for communal satationsite”, Comsat Laboratories Clarksburg, AIAA / NASA Spacesyst Technol.Conf. 14/8, 5-7 June, 1984).

The disadvantage of this method is that in the event of a failure of any battery and operation through "bypass" diodes, additional losses of electricity occur on the diodes themselves. In addition, the presence of a voltage drop across the / 0.4-0.6 / V diodes applied to the failed battery contributes to the occurrence of electrochemical reactions in the latter, which may lead to depressurization in some cases.

A known method of operating a Nickel-hydrogen battery by conducting charge-discharge cycles and bypassing a faulty battery, characterized in that the resistance value of the shunt battery circuit is selected from the condition:

R <0.3I, where

I - the maximum value of the current through the battery (see copyright certificate No. 1396881, Н 01 М 10/44).

The known method eliminates the above disadvantages, however, it does not define criteria for battery failure, which can lead to erroneous shunting of a working battery.

There is a known method of operating a nickel-hydrogen storage battery, an improved method according to copyright certificate N1396881, which controls the presence of capacity in the battery and the minimum voltage of the batteries, and bypassing the corresponding battery is carried out if there is capacity in the battery at the minimum voltage of this battery (copyright certificate No. 1795848) .

The disadvantage of this method is that it does not take into account the failure of the battery type "break" or increase the internal resistance of the battery in excess of the permissible value. Failures of this kind for nickel-hydrogen batteries may be due to hydrogen leakage due to a leak in the battery (see chapter X1.3 B.I. Tsenter, N.Yu. Lyzlov "Metal-hydrogen electric systems", Leningrad, Chemistry, Leningrad branch , 1989, pp. 265-266 [1]).

A complete sudden “break” of the battery is also real and was recorded during the vibration tests of the 28NV45 battery. The reason is a break in the battery electrode.

It should be noted that if the battery is completely “cut off” during charging of the battery, a voltage equal to the charging voltage minus the emf of the remaining (n-1) batteries will be supplied to the battery voltage monitoring sensor, that is, a value significantly exceeding the battery voltage limit value.

The closest technical solution is a method of operating a nickel-hydrogen storage battery by conducting charge-discharge cycles, monitoring the minimum voltage of the batteries to limit discharge and bypass the faulty battery, in which the maximum voltage of the batteries is further controlled at a level exceeding their maximum charging voltage, and bypass the faulty the battery is also carried out by this parameter (see patent No. 1836757 of October 13, 1992), which is selected as rototipa.

The disadvantage of all known operating methods associated with shunting a faulty battery is their insufficient reliability and cumbersome hardware implementation. So for the implementation of the known method in the satellite requires special equipment for monitoring the voltage of each battery, special equipment for switching on the heating of the heating coil of the short circuit and so on. In addition, to ensure full confidence that it is the faulty battery that is shorting, it is necessary either to integrate the battery voltage controllers in the design of short-circuiting devices or to excessively complicate the process of monitoring the correct address.

The known batteries described in B.C. Bagotsky, A.M. Skundin "Chemical current sources", Moscow, Energoizdat, 1981 [2].

Nickel-hydrogen storage batteries described in [1]) are known.

However, the known materials do not contain recommendations for protecting the battery from battery failures.

At present, the enterprise of Saturn OJSC in Krasnodar manufactures nickel-hydrogen storage batteries (for example, 40NV-70), which comprise 40 series-connected batteries, each of which is connected to bypass diodes and single-use short-circuit power circuits, and heating single-acting short-circuit circuits are routed to connectors for external control. The battery design is described in ZhTsPI.563533.012-01.

The same company manufactures nickel-hydrogen storage batteries having, along with discharge batteries, also charging bypass diodes, for example, a 28NV-50 battery (ZhTsPI.563533.019E3)

These batteries are taken as a prototype.

The aim of the invention is to increase reliability and simplify the process of shunting a faulty battery, as well as increasing the reliability and autonomy of the battery itself.

This goal is achieved by the fact that for shunting the battery, the appearance of current in the bypass diode circuits is controlled and by this parameter the battery is bypassed, and the heating elements of the single-acting short-circuit switches are included in the bypass diode circuits.

Indeed, on a working battery, the appearance of current in the circuit of its bypass diode clearly indicates a failure of this battery.

Moreover, the appearance of current in the circuit of the bypass diode is possible both in the event of a battery failure associated with the appearance of an internal shunt, and in the event of an “open” failure, and the appearance of current in the circuit of the charging bypass diode is possible only when an “open” type of failure occurs.

The operating experience of nickel-hydrogen storage batteries shows that failures of the “internal shunt” type are not unequivocally irreversible. In practice, cases of subsequent complete (or partial) spontaneous (or after special programs) restoration of the characteristics of previously faulty batteries have been noted. At the same time, a failure of the “cliff” type is definitely irreversible.

In this regard, the developer of an autonomous satellite power supply system needs to decide on what types of failures (internal shunt or “open”) it is necessary to bypass the battery on this satellite and depending on this, turn on the heating elements of the short-circuiting devices of one-time operation accordingly.

The implementation of the proposed method is expediently carried out in the battery itself, since additional (external) devices are not required for this.

This will improve the reliability and autonomy of the battery. In the event of a failure of any battery, the problem of restoring the battery’s performance is solved automatically by itself.

In the drawings, figures 1 and 2 shows the electrical circuits of the batteries for implementing the proposed method.

The battery contains A1 - An batteries connected in series.

Parallel to the batteries, charging bypass diodes D11, D12, D13 - Dn1, Dn2, Dn3, discharge bypass diodes D4 - Dn4 and disposable short-circuits K1 - Kn are connected.

The heating elements (windings) of the single-acting short-circuiting switches are included in the circuit of discharge bypass diodes - figure 1 and in the circuit of charging bypass diodes - figure 2.

When installing the heating elements of the short circuit in the circuit of the discharge diodes, the battery operates as follows.

If any battery A - An fails during operation due to the appearance of an internal shunt, the voltage across it will decrease to negative (due to its polarity reversal to a value limited by the voltage drop across the discharge diode plus the short-circuit heating element) and through the discharge diode and connected in series with with it, the heating element of the short circuit in the discharge mode of the battery starts to flow the discharge current of the battery (in the charge mode of the battery approx through the discharge diode will not flow). As a result, the circuit of the corresponding one-time short circuit will be closed and the flow of current through this diode and the heating element will stop. The battery will be reliably shunted, and the further operation of the battery will follow the same algorithm.

If the battery of any battery A - An fails, the discharge diode with the heating element of the short circuit simply appears in the discharge current circuit of the battery. Further, the disconnection of the corresponding battery from work will occur as in the event of an internal shunt.

When installing the heating elements of the short circuit in the circuit of the charging diodes, the battery operates as follows.

In the event of the failure of any battery A - An during operation due to the appearance of an internal shunt, the voltage on it will decrease to a negative value (due to its polarity reversal to a value limited by the voltage drop across the discharge diode) and the current will flow through the discharge diode in the discharge mode of the battery battery discharge. In battery charge mode, charging current will flow directly through the faulty battery.

If the battery of any battery A - An fails, the discharge diode will simply be in the discharge current circuit of the battery. In battery charge mode, charging current will flow through the charging diodes and the heating element of the corresponding short circuit in series.

As a result, the circuit of the corresponding one-time short circuit will be closed and the flow of current through these diodes and the heating element will stop. The battery will be reliably shunted and further operation of the battery will follow the same algorithm.

Thus, the proposed method can improve reliability and simplify the process of shunting a faulty battery in the battery, as well as increase the reliability and autonomy of the battery itself.

Claims (4)

1. A method of operating a nickel-hydrogen storage battery consisting of “n” series-connected batteries shunted by bypass diodes and short-circuiting bypasses by conducting charge-discharge cycles and bypassing the faulty battery by a short-circuiting bypasser, characterized in that they control currents in the circuits of discharge bypass diodes of each battery, and battery shunting is carried out when currents appear in them. 2. A storage battery containing “n” batteries connected in series, “n” discharge and “n” charging circuits of bypass diodes, “n” disposable short circuits containing heating circuits, and the discharge circuit and three series connected charging bypass diodes, and also disposable short circuits are connected in parallel to each accumulator, respectively, characterized in that the heating circuits of the single-action short circuits are included in the circuits of the bypass diodes with appropriate batteries. 3. A method of operating a nickel-hydrogen storage battery consisting of “n” series-connected batteries, shunted by bypass diodes and short-circuit short-circuits by conducting charge-discharge cycles and bypassing a faulty battery with a short-circuit short circuit breaker, characterized in that the currents in the circuits of three in series are controlled connected charging bypass diodes of each battery, and battery shunting is carried out when currents appear in them. 4. A storage battery containing “n” batteries connected in series, “n” discharge and “n” charging circuits of bypass diodes, “n” disposable short circuits containing heating circuits, and the discharge circuit and three series connected charging bypass diodes, and also disposable short-circuits are connected in parallel to each accumulator, respectively, characterized in that the heating circuits of the single-action short-circuits are connected in chains of three series-connected nnyh charging bypass diodes corresponding accumulators.

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