1. A swiveling work machine comprising:
a swivel deck mounted to be pivotable about a vertical axis; and
a side cover for covering one lateral side on the swivel deck, an accommodating space capable of accommodating a work machine accessory being provided inside said lateral cover;
wherein said accommodating space accommodates, as said implement accessory, a work oil tank, a fuel tank and a control valve unit; and
said work oil tank is disposed at a fore-and-aft intermediate portion on one lateral side on said swivel deck, said fuel tank is disposed forwardly of said work oil tank forming a gap relative thereto, and said control valve unit is disposed upwardly of said fuel tank and longitudinally along the foreaft direction.
2. The swiveling work machine according to claim 1, wherein said gap accommodates a battery therein, and said control valve unit is disposed upwardly of the battery and the fuel tank.
3. The swiveling work machine according to claim 2, wherein said battery and said control valve unit are supported to a support frame fixed to said swivel deck, and
wherein said support frame includes a pair of stays disposed erect on an upper face of the swivel deck at positions forwardly and rearwardly of the battery, a first plate mounted between vertical intermediate portions of the pair of stays and mounting the battery thereon, and a second plate connected to upper ends of the pair of stays and mounting the control valve unit thereon.
4. The swiveling work machine according to claim 3, wherein a front portion of the second plate extends to a position upwardly of the fuel tank.
5. The swiveling work machine according to claim 2, wherein at least one of a front lower portion of the work oil tank and a rear portion of the fuel tank extends into a portion of said gap on an inner side of the swivel deck relative to the battery.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A large scale energy storage system enabling balanced control of inverters, the large scale energy storage system comprising:
an inverter controller comprising a PWM generation circuit configured to generate a reference PWM signal and a first OE converter configured to convert the reference PWM signal transmitted from the PWM generation circuit into an optical signal and to output the optical signal; and
a plurality of PCS inverters configured to output a grid voltage, each of the PCS inverters comprising a second OE converter embedded therein to convert the PWM signal and the optical signal output from the inverter controller into an optical signal and a plurality of inverter modules.
2. The large scale energy storage system enabling the balanced control of the inverters of claim 1, wherein the PWM generation circuit is provided with an inverter reference output current applied from an external device and the output current and voltage output from each of the PCS inverters, and compensates an error between the reference output current and the output current and voltage and generates the reference PWM signal.
3. The scale energy storage system enabling the balanced control of the inverters of claim 1, wherein the inverter module comprises,
a PWM compensation circuit configured to calculate a phase and frequency of a grid and to output the PWM signal synchronized with the grid;
an inverter comprising a switching element configured to switch a supplied DC power into an AC power;
a reactor configured to suppress a harmonic wave from being output to a power supply by restricting the output current of the inverter;
a current deviation detector configured to measure a grid voltage with each phase, entire currents flowing the grid and a grid current for each of the inverters, the current deviation detector comprising a filter connected in serial to filter the noise generated from the power supply or the inverter; and
a PWM calculator configured to calculate a deviation of the entire currents based on the information detected by the current deviation detector and to supply the calculated deviation to the PWM compensation circuit.
4. The scale energy storage system enabling the balanced control of the inverters of claim 3, wherein the PWM compensation circuit compensates current imbalance between the inverter modules and a low frequency circulating current which are caused by property variation or temperature variation of the inverter, the reactor and the filter.
5. The scale energy storage system enabling the balanced control of the inverters of claim 4, wherein the PWM compensation circuit generates and supplies a compensated PWM signal, having a compensated width and a compensated phase of a pulse corresponding to the deviation, to the inverter, after measuring entire grid currents of each phase and a grid current of the inverter module and calculating a deviation for the entire grid currents.