JPS61104175A - Pressurized oil equipment - Google Patents

Abstract

PURPOSE:To economize energy, by stopping the rotation of an electric motor when the pressure of working oil is equal to a prescribed level within an allowable range for rated pressure. CONSTITUTION:A pressurized oil tank is provided with a pressure sensor 11 which detects the pressure of working oil. The output of the sensor 11 is entered into a controller 12 for an inverter 10. When the pressure of the working oil is equal to a prescribed level with an allowable range for rated pressure, the rotation of an electric motor 2 is stopped. An oil pump 1 can thus be stopped at the time of unloading, so as to economize energy.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a pressure oil device that supplies pressure oil for operating various FI devices in, for example, a hydroelectric power plant, and in particular, it relates to a pressure oil device that enables power-saving operation. This relates to a pressure oil device.

[Conventional technology]

In hydroelectric power plants, pressure oil is used to operate various tli devices (for example, speed regulating deep-in valves, pressure control devices, braking devices, etc.). The pressure oil device that supplies the pressure oil is, as shown in Fig. 3, a normal oil pump 1 and an electric drive motor [induction motor (IM)]2. ! Accumulator for 1 stroke3. Unloader (hydraulic switching valve) 4. Pressure oil tank5. Pressure oil piping6. Oil return valve 7, oil storage tank 8. It is composed of a filter 9 and the like.

The oil pump 1 pumps hydraulic oil (turbine oil) in the oil storage tank 8.
The oil is sent to the pressure oil tank 5 while mixing outside air to create pressure oil (pressure oil) in the pressure oil tank 5. This pressure oil is usually sent to the servo motors and pressure distribution valves of each unit under control by an electric circuit, and TL control of the units is performed, and when the work is finished, it is returned to the oil storage tank 8 as waste oil. The capacity of the pressure oil tank 5 is designed to be large enough to immediately stop the water turbine even if the pressure oil in the tank is no longer able to maintain the specified value due to loss of electric power or other failure, and is used as a safety device. A pressure oil relay (not shown) is provided.

The usage value of pressure oil is 10 to 70m/depending on the size of the water wheel etc.
An appropriate position within the range of ci is selected.

[Problem to be solved]

Conventionally, the oil pump 1 is continuously operated at a constant repair speed regardless of the state of the load (controlled am equipment), and the pressure in the pressure oil tank 5 is set to a set value [for example, rated pressure (14 kg,
cf) ±1b/c4).
detects the oil pressure and operates the unloader 4 located between the pressure oil tank 5 and the oil pump 1, and when it reaches -1 kg/c, hydraulic oil is supplied from the oil pump 1 to the pressure oil tank 5, and the oil pressure increases by +1 kg/c.
g/d, the unloader bypasses the pressure oil tank 5 to drain the hydraulic oil and return it to the oil storage tank 8. Therefore, the drive electric motor of oil pump 1 (■
N2) is operated continuously, and there is a considerable amount of wasted power consumption while draining the hydraulic oil, and improvements are desired from the point of view of energy conservation.

The object of the present invention is to solve the above-mentioned problems of the conventional art.

To provide a pressure oil device capable of saving energy by stopping the rotation of an oil pump except when the oil pump is supplying hydraulic oil to a pressure oil tank.

[Means for solving problems]

In order to achieve the above-mentioned object, the present invention uses an inverter [variable voltage variable frequency (VVVF) inverter] as the 1f source of the electric power garden that drives the oil pump. The rotational speed of the ivJ can be continuously varied from low to high speed, and a pressure sensor (semiconductor pressure sensor) for detecting the pressure of hydraulic oil is provided in the pressure oil tank (or pressure oil piping, etc.). Then, the pressure signal of the hydraulic oil detected by the pressure sensor is inputted.

The output of the inverter is controlled to vary the rotational speed of the oil pump driving electric motor to maintain the pressure oil tank within an allowable range of the set rated pressure.

[Effect]

According to the pressure oil HTa of the present invention described above, the rotation of the oil pump can be stopped except when the oil pump is supplying vJ oil to the pressure oil tank, thereby saving power. In addition, since the rotation of the electric motor is controlled by an inverter, acceleration, deceleration, and stopping can be repeated 11 times at will.
t< stress can also be reduced. Details of this operation mode will be explained in the next example.

〔Example〕

The pressure oil system of the present invention is the one shown in Fig. 3 with the addition of an inverter and a control system for controlling it, and the basic configuration of equipment 4 is the same as that shown in Fig. 3 (however, the unloader is no longer required). ), we will mainly explain the configuration and operation of the newly added parts.

FIG. 1 is an Rf block diagram showing the configuration of the main part of the present invention (control TLL system of the oil pump driving electric motor). As shown in the figure, an inverter (VVVF inverter) 10 as a power source for an electric motor (1M) 2 that drives an oil pump 1 and a pressure sensor (semiconductor pressure sensor) 11 for detecting the pressure in a pressure oil tank 5 are installed. It is provided. The inverter 10 has a control section 12 built in or added to the inverter (output control is performed by the control section 12).

The control unit 12 inputs the pressure signal detected by the pressure sensor 11 and has a maximum pressure detector 23121 and a minimum pressure detector 122 that detect the maximum and minimum pressures set in the pressure oil tank 5.
, a fixed charge/discharge cycle for setting the acceleration time and deceleration time of the electric train 2 by inputting the detection output signals from these surface detectors, and the maximum speed setting circuit 1 of the electric train t12.
24. A minimum speed setting circuit 125 and a 3112 command signal generation circuit 126 that generates a signal to control the inverter 10 based on the motor operation mode setting signal obtained through each of the above-mentioned circuits are combined.

The control unit 12 is provided with various settings (consisting of potentiometers, for example) for setting the operation mode, namely: (1) a setting device for deceleration interval setting;
The acceleration time pit setting device is the constant current charging/discharging circuit 123 mentioned above.
■The setting device for setting the maximum speed is the maximum speed setting circuit 124.
■The setting device for setting the lowest speed is the lowest speed setting circuit 125.
It is set in.

The il 1 part 12 configured in this way is the pressure sensor 1
ff
1vJfi 2 and the rotational speed of the oil pump 1 connected thereto.

Next, the operation of the pressure oil system of the present invention will be explained with reference to the operation mode shown in FIG.

As shown in Figure 2 (a), the pressure in the pressure oil tank changes over time <
1>. Now, let us assume that the rated pressure of the pressure oil tongue is, for example, 14's-'d, and the allowable range is, for example, ±1.
kg/d. In the conventional pressure adjustment using an unloader, adjustment was performed according to the pressure change shown by the dotted line. In the unloader, the valve is switched to the on-load side during the time when the pressure in the pressure oil tank is increased from the allowable minimum pressure (13 kg/cd) to the allowable maximum pressure (15 kg/cd), and to the unload side during the other times. This onload period is usually 20-30 seconds, and the unload period is 3-30 seconds.
It takes about 10 minutes. The present invention aims to save energy by stopping the rotation of the electric motor and oil pump during this good unloading period.Therefore, in the present invention, adjustments are made in accordance with the pressure changes shown by the solid line in Fig. 2 (a). . Adjustment is done by controlling the rotation of the oil pump based on the pressure signal from the pressure sensor, so if you turn on or off the electric n only after the pressure in the pressure oil tank reaches the allowable minimum pressure and the allowable maximum pressure. is gradually accelerated and decelerated, and there is a time when the oil pressure gradually rises and falls accordingly, which may cause the oil pressure supply to become unstable. 1 so that mati is turned on and off by pressure signals at pressure levels A (for example 13.3 kg/cd) and B (for example 14.7 kg, 'c).
.

There is. That is, the rotation of the evening print is as shown in FIG. 2 (b). The output of the pump at this time is as shown in Fig. 2 (c). If the oil pump is operated according to this operation mode, not only will the hydraulic pressure be stably supplied, but also the second
As shown in Figure (b), there is time for the electric motor to stop, thereby saving power.

In the above explanation, we have explained the case where the oil pump is stopped during the unloading period, but this assumes that a gear pump, for example, is used as the oil pump, and the bearing (fifth wheel bearing) needs to be lubricated. Because I thought it wasn't. if,
If the oil pump uses a metal bearing, such as a screw pump, the inverter output can be set in advance so that the bearing rotates at the minimum speed required during the unloading period. good.

In addition, although the pressure oil device of the present invention does not require an unloader,
If the existing lff1 is equipped with an unloader, you can leave it as is and start operating 1hll!
It does not cause any problems with IT.

〔effect〕

As explained above, according to the present invention, the electric motor for the pressure oil pump is operated by a VVVF inverter, and the rotating sub-section can be freely performed, and the oil pump can be stopped at the time of unloading, which greatly reduces power consumption. can be reduced to Moreover, since the operation mode can be freely set, stable operation can be achieved with less bivi stress. In addition, the detection width of pressure changes can be narrower than in the case of an unloader (with an unloader, it is ±1!1/cd, and with a pressure sensor, it is
g, ' cd ) C hydraulic oil pressure becomes more stable.

In addition, the unloader is no longer required and the conventional tilting machine control is replaced with electric control, so it is easier to install! ! Furthermore, maintenance costs can also be reduced.

According to the results of 9 actual experiments, the power consumption ω due to the operation method of the present invention is lower than that of the conventional constant speed continuous operation method 1)! ! ! It turns out that it only requires about 30 to 40% of the electric power m, and the energy saving effect is very large.

[Brief explanation of the drawing]

Fig. 1 is a block diagram showing the configuration of the control system for the oil pump sabotage motor control system of the present invention, Fig. 2 (a) to (c) are explanatory diagrams of the operation modes of the pressure oil device of the present invention, and Fig. 3 is an explanatory diagram of the configuration of pressure oil & reed. 1... Oil pump, 2... Electric 1fi (IM), 4... Unloader, 5... Pressure oil tank, 8... Oil storage tank, 10... Inverter (VVVF inverter),
11...Pressure sensor, 12...Control unit.

Claims (1)

[Claims] 1. Pressure oil comprising a pressure oil tank, an oil storage tank for storing hydraulic oil, an oil pump for supplying hydraulic oil to the pressure oil tank, and an electric motor for driving the oil pump. In the device, a pressure sensor that detects the pressure of the hydraulic oil, an inverter for operating the electric motor, and a control unit that controls the output of the inverter are added, and the control unit is configured to control the pressure of the hydraulic oil detected by the pressure sensor. A signal is input, and in response to the input signal, the control unit generates an inverter control signal according to a preset operating mode, and based on the control signal, the inverter controls the rotational speed of the electric motor that drives the oil pump. A pressure oil device characterized in that the rotation of the electric motor is stopped when the pressure of the hydraulic oil is at a predetermined value within an allowable range of rated pressure.