RU2168828C1 - Method for controlling off-line power supply system - Google Patents

Abstract

FIELD: recovery of off-line power system functions upon long-time outages. SUBSTANCE: upon arrival of signal indicating critical degree of discharge of certain battery signal inhibiting operation of respective discharging device is entered. Respective battery is changed over to storage mode. If capacity of operating batteries and discharging devices turns out to be insufficient for feeding on-board loads upon inhibiting operation of some of discharging devices, all discharging devices and also voltage regulator supplying load with power from solar batteries (voltage regulator) are disabled, and discharging devices are not controlled by signals indicating degree of charge of storage batteries any more. In this case system is changed over to storage mode. At the same time serviceability check of all storage batteries goes on. In case of danger of polarity reversal in cells of any storage battery, polarity reversal protective gear is connected to them. Upon recovery of equipment orientation to sun batteries are first charged to certain value of total capacity and then (after desired number of batteries are charged to required level) operation of voltage regulator, discharging devices, and charged storage batteries is enabled, and discharging devices are controlled in response to signals indicating degree of charge. EFFECT: improved characteristics of system output voltage during and after off- optimum or emergency situation such as loss of solar battery orientation to sun. 2 dwg

Description

 The invention relates to electrical engineering, namely, power supply systems (SES) of autonomous objects using solar batteries (SB) as primary energy sources, and storage batteries (AB) as energy storage devices.

 A known method of controlling an autonomous power supply system containing a solar battery (SB), a voltage stabilizer (SN), connected between the solar battery and the load, n batteries (n≥1) and n (according to the number of batteries) of charging (memory) and discharge ( RU) devices, as well as for each battery - devices for monitoring the degree of charge.

In FIG. 1 shows a well-known functional diagram of such an SES [1], where it is indicated:
1 - solar battery (SB);
2 - voltage stabilizer (CH);
3 ₁ ... 3 _n - chargers (chargers);
4 ₁ ... 4 _n - bit devices (RU);
5 ₁ ... 5 _n - storage batteries (AB);
6 ₁ ... 6 _n - devices for monitoring the degree of charge of the battery (UKZB);
OS - feedback input;
Z - entry of the prohibition of work;
P is the input of the work permit;
7 - load SES (on-board consumers).

 In the SES, the voltage stabilizer, charging and discharge devices are continuously controlled depending on the input (voltage of the SB) and the output voltage of the SES. At the same time, the chargers provide a charge for the batteries, while the SN and RU provide power to consumers.

 Continuous control circuits (feedback - OS) of the charger are connected to the SB bus, and continuous control circuits (OS) of SN and RU are connected to the load bus.

 Depending on the degree of charge or discharge of the battery, a ban or permission to operate the charger and switchgear is made.

Upon reaching the maximum degree of charge of a specific battery, the signal from the output "Prohibition of memory" of its device for monitoring the degree of charge of the battery (6 ₁ ... 6 _n in Fig. 1) prohibits the operation of its memory. After discharging the battery to a predetermined level, this prohibition is removed by a signal from the "Permission of the memory" output of the UKZB.

Upon reaching the maximum degree (depth) of discharge of a specific battery, the signal from the "Prohibition of RU" output of its UKZB (6 ₁ ... 6 _n in Fig. 1) prohibits the operation of its RU. After charging this battery to a predetermined level, this prohibition is removed by a signal from the “Permission of RU” output of the UKZB.

Such management provides long-term full-time work of the SES. However, it does not ensure the preservation of the performance of SES in case of emergency or emergency situations at an autonomous facility. In the event of an abnormal, unplanned violation of the orientation of the solar panels of the object to the Sun, a violation of the energy balance in the SES occurs. If the loss of orientation is long enough, a complete discharge of all batteries may occur. Food on-board consumers will then stop
After the orientation of the object’s solar batteries is restored, the power supply to the on-board consumers will resume through the MV, and the battery will be charged through the charger. However, both during a full discharge of the battery and during storage of a discharged battery, the reverse polarity of individual batteries can occur, since the state monitoring devices remain connected to the battery and, therefore, along with the battery self-discharge, some external battery discharge current remains. Complete disconnection of control devices from the battery is most often impractical. Re-polarized batteries will fail and it will be impossible to restore them. The performance of batteries with polarity reversed batteries, and therefore the SES as a whole, will be lost.

 If the orientation of the object is lost or at the initial moment of the restoration of the SB orientation to the Sun, their illumination is random and may not be enough to provide power to consumers.

 The voltage at the SES output provided by the SN is determined by the ratio of the load power connected to the output buses of the SES and the power generated by the SB and determined by the degree of its illumination.

 The nature of the change in the power of the SB in these cases is unpredictable. The voltage of the SB and, therefore, the voltage of the on-board consumers can vary arbitrarily for an indefinite time, until the orientation is completely restored, in the range from 0 to the nominal value. For some electronic or electromechanical devices this is unacceptable. A number of on-board consumers may be affected.

 The proposed method solves the problem of preventing the failure of AB batteries, restoring the normal functioning of the SES after long interruptions in its operation, and improving the quality of the output voltage of the SES during and after an emergency or emergency.

 According to the proposed method, this problem is solved as follows.

 In an autonomous power supply system containing SB, n rechargeable batteries (n≥1), SN connected between the solar battery and the load, and n charge and discharge devices control the voltage stabilizer and charge-discharge devices depending on the input and output voltage of the system; control the degree of charge and discharged batteries; prohibit the operation of the corresponding memory when reaching the maximum level of charge of this battery, remove this ban when a certain level of discharge of this battery is reached; prohibit the operation of the corresponding switchgear when reaching the maximum level of discharging this battery and remove this ban when reaching a certain level of charge of this battery.

 If, after the prohibition of the operation of some switchgear, the power of the remaining AB and switchgear remaining in operation is insufficient to provide power to the on-board consumers, the work of all working switchgear and the SN is prohibited by this time, and the switchgear is terminated by the UKZB signals. SES completely goes into storage mode. At the same time, the state of all ABs is continued to be monitored. In the event of a danger of battery reversal of any battery, a battery protection device against reverse polarity is connected to them.

 After restoring the orientation of the object’s solar batteries to the Sun, the batteries are first charged to a certain value of the total capacity, and then (after the number of batteries charged to the required level of battery reaches a predetermined level), the SN and RUs of the charged batteries are allowed to operate, and the RCs are allowed to be controlled by UKZB signals.

 An example of the SES functional diagram in which the proposed method is implemented is shown in FIG. 2.

Here:
1 ... 7 - the same as in FIG. 1;
8 ₁ ... 8 _n - battery protection devices from reverse polarity;
On / Off - on / off input;
9 - a device for determining the possibility of turning on an SES (a unit for calculating charged batteries);
10 - a device for determining the need to disable SES;
11 ₁ ... 11 _n - logical elements OR;
12 ₁ ... 12 _n - functional elements - managed keys.

 The control method of SES is as follows.

 When each battery is discharged to the maximum level, the signal from the “Prohibition of RU” output of the corresponding monitoring device 6 through the OR logic element is input to the prohibition of the operation of the corresponding RU, thus stopping the discharge of the AB. This battery is in storage mode. At the same time, they continue to monitor her condition. If there is a danger of reverse polarity of the batteries of this battery, a device for protecting batteries from reverse polarity is connected to them. The connection signal can be, for example, a decrease in voltage on any battery (or group of batteries) to the minimum acceptable level. Schematic implementation of the device for protecting batteries from reverse polarity can be different. For example, for nickel-cadmium batteries, its function can be performed by a pre-discharge device, which is a set of resistors connected in parallel to each battery of the battery and used during preventive cycles to balance the state of charge of the batteries. This device is controlled both by external control commands from the digital computer during preventive cycles, and by signals from the AB monitoring device.

 After switching off this switchgear, the load is powered by the switchgear of other batteries that have not yet reached the maximum level of discharge.

In the event that after the prohibition of the operation of several (any) switchgear, the remaining power of the remaining batteries and the switchgear is insufficient to provide power to the on-board consumers, a signal appears at the output of device 10, which is fed to the input of the ban on the operation of the MV, opens the contacts 12 ₁ ... 12 _n , blocking the signals of UKZB to allow the operation of the switchgear, through logical elements OR 11 ₁ -11 _n prohibits the operation of all switchgears. Food on-board consumers ceases. SES completely goes into storage mode. The signal to switch the SES to storage mode can be, for example, a decrease in the voltage on the output buses of the SES to a certain value (if there is a lack of power for the operating switchgear, the output voltage of the SES starts to decrease), or a ban on the operation of a certain number of switchgears, or both.

 Thus, in the event of an abnormal or emergency situation at the facility (loss of orientation of the SB to the Sun), the power of on-board consumers is turned off, the batteries are in storage mode with protection from reverse polarity, and all RPs and MVs are prohibited.

In the event of a random appearance of the SB illumination or restoration of the SB orientation on the Sun, the AB charge will begin to be realized. Some time after the start of the charge, the voltage on the batteries will increase above the minimum allowable and the battery protection devices from reverse polarity are disconnected from the battery according to the UKZB 6 signals. Since the contacts 12 ₁ ... 12 _{n are} open, then the operation of specific switchboards after reaching the corresponding charge level of individual batteries not happening. First, k AB battery will be charged (k is in the range from 1 to n) to a certain level of total capacity. This level and quantity k of batteries can vary depending on the characteristics of the facility and is determined by the designer of the SES.

Upon reaching the required level of charge for k rechargeable batteries, the signal from the output of the device for determining whether the SES 9 can be turned on removes the ban on the operation of MVs, and also removes the blocking of the permission to operate all switchgear (contacts 12 ₁ ... 12 _n close). Through closed contacts 12, the signal from the AB control devices that have reached the specified charge level allows the operation of the corresponding ABs. Consequently, the operation of SN and RU connected to charged to the required level of AB will be allowed. Power supply for on-board consumers is renewed from MV or from RU depending on the ratio of the load power and the power generated by the SB. Since the batteries are charged, the voltage at the output of the SES will be equal to the nominal. Thus, with the proposed control method, there is no power supply mode for on-board consumers with substandard voltage that varies unpredictably from 0 to the nominal value, and excessive battery discharge is not allowed and the battery is protected from failure during storage.

Literature
1. RF patent N 2059988, cl. H 02 J 7/35, 1991

Claims (1)

 A method for controlling an autonomous power supply system containing a solar battery and n rechargeable batteries, where n ≥ 1, a voltage regulator connected between the solar battery and the load and n charging and discharging devices each, comprising controlling a voltage stabilizer and charge-discharge devices depending on the input and the output voltage of the system, control of the degree of charge and discharged batteries, the prohibition of the operation of the corresponding charger when reaching the limit level charging the given battery, removing this prohibition when a certain level of discharging the given battery is reached, prohibiting the operation of the corresponding discharge device when reaching the maximum level of discharging this battery, removing this prohibition when reaching a certain level of charge of this battery, characterized in that in case of loss of orientation of the solar panels in the sun, emergency discharge of batteries and disconnection of part devices, when the capacity of the remaining discharge devices is not enough to power the load, prohibit the operation of all discharge devices and the voltage regulator, and also stop the management of discharge devices by signals about the level of charge, after which, in case of danger of battery reversal of any battery, the device is connected to it protect batteries from polarity reversal, after restoring the orientation of solar batteries to the Sun, first recharge the batteries until cerned capacitance value, and then allow the voltage stabilizer job and resume control bit devices by signals on the level of charge, battery protection device disable field polarity battery charge start.

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