A motor driving system has a first motor, a first motor driving control device for driving the first motor, a second motor, a second motor driving control device for driving the second motor, a controller performing communication with the first motor driving control device and the second motor driving control device, a first communication line for connecting a common terminal of the controller and the first motor driving control device; a second communication line for connecting the common terminal and the second motor driving control device, and a switch unit capable of switching each of the first and second communication lines between an enable state in which communication is possible by the communication line and an disable state in which communication is impossible under control of the controller. The controller controls the switch unit to set either the first or the second communication line to the enable state.

A motor driving system has a first motor, a first motor driving control device for driving the first motor, a second motor, a second motor driving control device for driving the second motor, a controller performing communication with the first motor driving control device and the second motor driving control device, a first communication line for connecting a common terminal of the controller and the first motor driving control device; a second communication line for connecting the common terminal and the second motor driving control device, and a switch unit capable of switching each of the first and second communication lines between an enable state in which communication is possible by the communication line and an disable state in which communication is impossible under control of the controller. The controller controls the switch unit to set either the first or the second communication line to the enable state.

A gas pressure within a treatment chamber 2 can be more accurately regulated to a predicted target pressure whereby there can be provided a pressure control apparatus which can easily and speedily regulate the gas pressure for various combination of the treatment chamber 2, a sanction chamber 3 and a valve 4. A required inflow rate (Qi) at which it is necessary for gas to flow into the treatment chamber 2 in order to reach a preset target pressure (Psp) within the treatment chamber is calculated on the basis of the expression of Qi=Qo+(P/t)V and the thus calculated required inflow rate (Qi) is flown into the treatment chamber 2 to control the pressure within the treatment chamber 2 to the required pressure (Psp). In calculation of a current predicted outflow rate (Qo(n)) at which gas is discharged from the treatment chamber on the basis of the expression Qo(n)=P2*f1(P2), using a current pressure (P2) within the suction pump and a known characteristic suction rate (Sp=f1(P2)) of the suction pump under prescribed pressure, the current pressure (P2) within the suction pump is calculated according to the expression P2=P1(Qo(n1)/f2(, P)) from an accurate conductance (Cv(, P)=f2(, P)) calculated by adding the error between the current pressure (P1) actually measured within the treatment chamber and a known specified pressure (P) within the treatment chamber at the characteristic conductance (Cv=f2()) of the valve at the opening/closing angle () associated with the current position of the switching plate of the valve to the known characteristic conductance (Cv=f2()) of the valve at the opening/closing angle () associated with the current position of the switching plate of the valve, and the current predicted outflow rate Qo(n) at which gas is discharged from the treatment chamber is calculated.

A motor driving system has a first motor, a first motor driving control device for driving the first motor, a second motor, a second motor driving control device for driving the second motor, a controller performing communication with the first motor driving control device and the second motor driving control device, a first communication line for connecting a common terminal of the controller and the first motor driving control device; a second communication line for connecting the common terminal and the second motor driving control device, and a switch unit capable of switching each of the first and second communication lines between an enable state in which communication is possible by the communication line and an disable state in which communication is impossible under control of the controller. The controller controls the switch unit to set either the first or the second communication line to the enable state.

A motor driving system has a first motor, a first motor driving control device for driving the first motor, a second motor, a second motor driving control device for driving the second motor, a controller performing communication with the first motor driving control device and the second motor driving control device, a first communication line for connecting a common terminal of the controller and the first motor driving control device; a second communication line for connecting the common terminal and the second motor driving control device, and a switch unit capable of switching each of the first and second communication lines between an enable state in which communication is possible by the communication line and an disable state in which communication is impossible under control of the controller. The controller controls the switch unit to set either the first or the second communication line to the enable state.

A gas pressure within a treatment chamber 2 can be more accurately regulated to a predicted target pressure whereby there can be provided a pressure control apparatus which can easily and speedily regulate the gas pressure for various combination of the treatment chamber 2, a sanction chamber 3 and a valve 4. A required inflow rate (Qi) at which it is necessary for gas to flow into the treatment chamber 2 in order to reach a preset target pressure (Psp) within the treatment chamber is calculated on the basis of the expression of Qi=Qo+(P/t)V and the thus calculated required inflow rate (Qi) is flown into the treatment chamber 2 to control the pressure within the treatment chamber 2 to the required pressure (Psp). In calculation of a current predicted outflow rate (Qo(n)) at which gas is discharged from the treatment chamber on the basis of the expression Qo(n)=P2*f1(P2), using a current pressure (P2) within the suction pump and a known characteristic suction rate (Sp=f1(P2)) of the suction pump under prescribed pressure, the current pressure (P2) within the suction pump is calculated according to the expression P2=P1(Qo(n1)/f2(, P)) from an accurate conductance (Cv(, P)=f2(, P)) calculated by adding the error between the current pressure (P1) actually measured within the treatment chamber and a known specified pressure (P) within the treatment chamber at the characteristic conductance (Cv=f2()) of the valve at the opening/closing angle () associated with the current position of the switching plate of the valve to the known characteristic conductance (Cv=f2()) of the valve at the opening/closing angle () associated with the current position of the switching plate of the valve, and the current predicted outflow rate Qo(n) at which gas is discharged from the treatment chamber is calculated.

Power network monitoring systems are presented. In some embodiments, the system includes a master device installed in at least one substation among the plurality of substations, and slave devices installed in remaining substations except from the substation in which the master device is installed. Each of the slave devices may include a first PMU configured to measure data such as reactive/active power, magnitudes and phase angles of a voltage and current of the substation in which the slave device is installed. The master device may analyze data transmitted from each of the slave devices, may generate a command for taking action of a corresponding slave device based on an analyzed result, and may transmit the generated command to the corresponding slave device.

Power network monitoring systems are presented. In some embodiments, the system includes a master device installed in at least one substation among the plurality of substations, and slave devices installed in remaining substations except from the substation in which the master device is installed. Each of the slave devices may include a first PMU configured to measure data such as reactive/active power, magnitudes and phase angles of a voltage and current of the substation in which the slave device is installed. The master device may analyze data transmitted from each of the slave devices, may generate a command for taking action of a corresponding slave device based on an analyzed result, and may transmit the generated command to the corresponding slave device.