1、 1 Description Technical Field The present invention relates to a power source system having a power accumulator for supplying when a commercial power source oe other interruptible power source breaks down,a power supply control method Of the power source system,a power supply control program Of the
2、 power source system,a computer readable recoding medium having power supply control program Of the power source system recoded thereon. Background Art In recent years ,a power accumulator has drawn wide attention and been used as backup power source.A backup power source is changed when a commercia
3、l power source operated normally,and continues supply power to equipment in place of the commercial power source when commercial power source has a defect.Examples of such a backup power source include a UPS （ Uninterruptive Power Source ） .By instantaneously switching the commercial power source to
4、 an output of the backup power source in case of power outage,a computer or a storage unit in use,as well as network equipment such as a server are prevented from being stopped. Such a backup power source combined with the power accumulator is controlled to maintain residual capacity representing th
5、e state of charge at a high level.In this system,generally because surplus power is charged in power accumulator efficiently by a power generation action of an electric motor,charge|discharge control is performed so that the SOC does not exceed 100%.In order to supply power to the electric motor whe
6、n necessary,charge|discharge control is performed so that the SOC does not decrease to 0(zero).Specially,normally in power accumulator,the control is performed so that the SOC fluctuates within a range of 20% to 80%. With regard to elevators,on the other hand,a hybrid elevator that has a cage and a
7、counterweight to inhibit unnecessary power consumption during the operation of hybrid elevator has been developed.Such a hybrid elevator utilizes the power of its battery at the time of power outage,so that in case of power outage or other abnormal state during of operation of the hybrid elevator,th
8、e power for driving the elevator is supplied from a power source to carry the elevator to the nearest floor or any floor and safely retrieve the passage from the stage. 2 The following method is proposed as a method for controlling an automatic landing device of the elevator.Patent Document 1,for ex
9、ample,discloses a method for detecting the output voltage ,output current,and a temperature of a battery power source to perform a rescue operation in response to the power supply capacity of the battery power source. Here,as a method for calculating the power supply capacity,a method for calculatin
10、g the power supply capacity from the open voltage,internal resistance,and minimum voltage(operable voltage) of the battery power source is generally known ,as shown is equation (1) below.The minimum voltage used for calculating the power supply capacity is set with a certain degree of margin,in view
11、 of the life of the battery power source . Power Supply Capacity= minimum voltage*(open voltage - minimum voltage)internal resistance.(1) Moreover,the hybrid elevator has to always secure energy amount for carrying the elevator to a necessary floor in case of emergency during the normal operation of
12、 commercial power source ,and thereon a large power accumulator with a large capacity required. In the method disclosed in Patent Document 1,the output voltage and the voltage set value are compared with each other by a discharge time and discharge state of the battery is detected by the magnitude r
13、elation there between to control the operation of the elevator.Therefore,when the power supply capacity of the battery power source is low,the power supply capacity will be lost,thereby stopping the power supply from the battery.In this case,because charging of the battery power source is started af
14、ter the interruptible power source returns ,and the rescue operation is conducted upon completion of the charging,the elevator cannot be carried to the nearest floor to perform rescue operation in the case of an abnormal situation of the interruptible power source.As a result,the passengers remain t
15、rapped in the elevator. Moreover,when the interruptible power source is stopped due to disaster like as in the hybrid elevator,it is necessary for the backup power source to ensure the minimum power supply capacity for enabling minimum operation. Consequently,because a margin becomes necessary in th
16、e capacity of the backup power source,a large power accumulator is necessary. In addition,the minimum voltage used for calculating the power supply capacity has a margin,in view of the life property.Therefore, 3 the value of the actual power supply capacity is smaller than the that of the primary po
17、wer supply capacity of the power accumulator. Disclosure of invention An object of the present invention is to provide a power source system capable of realizing at least the minimum backup function ,increasing the life duration of a power accumulator,and reducing the size of the power accumulator b
18、y temporarily improving the power supply capacity of a power accumulator when an interruptible power source is stopped by disaster or the like.The present invention also provide a power supply control method of the power source system ,a power supply control program Of the power source system and a
19、computer readable recoding medium having power supply control program Of the power source system recoded thereon. A power source system according to an aspect of the present invention has:a power unit for supplying power to a load service；a power accumulator for supplying the power to a load service
20、 in place of the power unit when the power unit is stopped,and a controller for controlling power supply from the power accumulator to a load service；wherein the controller sets an operable voltage,which is determined as an output voltage foe ending discharge of the power accumulator,at a first volt
21、age when the power unit is operated,and sets the operable voltage at a second voltage lower than the first voltage when the power unit is stopped ,thereby increasing the power supplied to the load device by the power accumulator. According to the power source system described above,the power supply
22、capacity of the power accumulator can be improved by reducing the operable voltage of the power accumulator when the power unit is stopped,the operable voltage being set during the normal operation of the power unit.Furthermore,because the operable voltage of the power accumulator is reduced after t
23、he power unit is stopped,and the number of the times that the power accumulator is over-discharged duo to the decrease in the operable voltage can be prevented from increasing.,the life duration of the power accumulator can be increased.In addition,the size of the power accumulator can be reduced be
24、cause it is not necessary to increase the capacity of the power accumulator beforehand in the light of an increase in power supply when the power unit is stopped. Brief description pf the drawings: Fig.1 Fig.1 is a block diagram showing a configuration of a power source system according to Embodiment 1 of the present invention.
