Hydraulic system and wind turbine generator provided therewith

• US 9,169,829 B2
• Filed: 10/28/2009
• Issued: 10/27/2015
• Est. Priority Date: 10/29/2008
• Status: Active Grant

• Current Assignee: Mitsubishi Heavy Industries, Ltd.
• Original Assignee: Mitsubishi Heavy Industries, Ltd.
• Inventors: Yuge, Atsushi, Hayashi, Toshikazu, Nomaguchi, Hiroyuki
• Primary Examiner(s): YOUNGER, SEAN JERRARD
• Application Number:
  US12/588,784
• Publication Number:
  US 20100104439A1
• Time in Patent Office: 2,190 Days
• Field of Search: 184/6.4, 184/6.12, 184/6.13, 415/111, 415/112, 416/170.R, 416/174, 417/2
• US Class Current: 1/1
• CPC Class Codes: F03D 7/02 the wind motors having rotation axis substantially parallel to the air flow entering the rotor
• CPC Class Codes: F03D 9/00 Adaptations of wind motors for special use; Combinations of wind motors with apparatus driven thereby; Wind motors specially adapted for installation in particular locations hybrid wind-photovoltaic energy systems for the generation of electric power H02S10/12
• CPC Class Codes: F03D 9/10 Combinations of wind motors with apparatus storing energy
• CPC Class Codes: Y02E 10/72 Wind turbines with rotation axis in wind direction
• CPC Class Codes: Y02E 70/30 Systems combining energy storage with energy generation of non-fossil origin
• CPC Class Codes: Y02P 80/10 Efficient use of energy, e.g. using compressed air or pressurized fluid as energy carrier

Abstract

There is provided a hydraulic pump startup control device in a hydraulic system, which avoids an overloaded state at startup to enable low-temperature, fast startup and maintaining of the temperature with low-cost means in order to improve low-temperature startability. A bypass path 19 is placed in parallel with a hydraulic main line from a hydraulic tank, and the downstream of the bypass path is made merged with the hydraulic main line. A bypass valve 3 that opens or closes the bypass path is provided in the bypass path, and a pressure sensor is provided in the inlet of a hydraulic unit in the hydraulic main line. Further, a control device 10 to which a pressure detection value in the hydraulic main line is input from the pressure sensor to open the bypass valve based on the pressure detection value upon startup of the hydraulic unit. The control device repeats on-off control to circulate oil in the bypass path while keeping the pump discharge pressure and the flow rate to open the bypass path at startup so that the actuation power of the hydraulic unit will become the maximum in order to rise the hydraulic temperature of the hydraulic main line.

Claims

1. A hydraulic system adapted to feed oil from a hydraulic tank into a hydraulic unit, the hydraulic system comprising:

a hydraulic main line for connecting the hydraulic tank and the hydraulic unit;

a hydraulic pump placed in the hydraulic main line, the hydraulic pump feeding the oil from the hydraulic tank into the hydraulic unit through the hydraulic main line to actuate the hydraulic unit;

a bypass path branching off from a discharge side of the hydraulic pump in the hydraulic main line to the hydraulic tank;

a flow rate control means provided in the bypass path to control a flow rate of the bypass path;

a pressure sensor provided in an inlet of the hydraulic unit in the hydraulic main line;

a control device to which a pressure detection value is input from the pressure sensor to control the flow rate control means based on the pressure detection value; and

a temperature sensor for detecting a temperature of the oil and inputting a temperature detection value to the control device,

wherein the oil is circulated in the bypass path while keeping a pump discharge pressure and the flow rate equal to or smaller than given specified values, and

wherein the control device is configured;

to circulate the oil in the bypass path while controlling the flow rate control means in order to keep an actuation power of the hydraulic pump equal to a maximum value based on the pressure detection value and a set curve of an actuation power of the pressure and the flow rate of the hydraulic unit, when the temperature detection value is lower than a predetermined temperature; and

to perform control to stop circulating the oil in the bypass path, when the temperature detection value reaches the predetermined temperature.

2. The hydraulic system according to claim 1, wherein the flow rate control means is a variable flow valve that controls the flow rate of the bypass path.

3. A wind turbine generator provided with the hydraulic system according to claim 1.

5. The hydraulic system according to claim 2, wherein the variable flow valve includes a flow restrictor, and the control device controls the flow restrictor in order to set the pressure detection value at a pressure value relative to the maximum value of the actuation power of the hydraulic pump.

6. The hydraulic system according to claim 1, further comprising a check valve arranged in the hydraulic main line between a portion branching off into the bypass path and the pressure sensor, and an air breather provided in the hydraulic tank.

7. The hydraulic system according to claim 6, wherein the temperature sensor is provided in the hydraulic tank and the flow rate control means is a variable flow valve to controls the flow rate of the bypass path, and the variable flow valve closes the bypass path, when the temperature detection value reaches the predetermined temperature such that the oil is fed from the hydraulic tank into the hydraulic unit through the check valve in the hydraulic main line.

4. A hydraulic system adapted to feed oil from a hydraulic tank into a hydraulic unit, the hydraulic system comprising:

a hydraulic main line for connecting the hydraulic tank and the hydraulic unit;

a hydraulic pump placed in the hydraulic main line, the hydraulic pump feeding the oil from the hydraulic tank into the hydraulic unit through the hydraulic main line to actuate the hydraulic unit;

a bypass path branching off from a discharge side of the hydraulic pump in the hydraulic main line to the hydraulic tank;

a flow rate control means provided in the bypass path to control a flow rate of the bypass path;

a pressure sensor provided in an inlet of the hydraulic unit in the hydraulic main line;

a control device to which a pressure detection value is input from the pressure sensor to control the flow rate control means based on the pressure detection value; and

a temperature sensor for detecting a temperature of the oil and inputting a temperature detection value to the control device,

wherein the oil is circulated in the bypass path while keeping a pump discharge pressure and the flow rate equal to or smaller than given specified values,

wherein the flow rate control means is a bypass valve that opens or closes the bypass path, and

wherein the control device is configured;

to perform control in order to set the pressure detection value at a pressure value where a maximum value of an actuation power of the hydraulic pump is obtained based on a set curve of an actuation power of the pressure and the flow rate of the hydraulic unit, when the temperature detection value is lower than a predetermined temperature; and

to perform control to stop circulating the oil in the bypass path, when the temperature detection value reaches the predetermined temperature.

8. A hydraulic system adapted to feed oil from a hydraulic tank into a hydraulic unit, the hydraulic system comprising:

a hydraulic main line for connecting the hydraulic tank and the hydraulic unit;

a hydraulic pump placed in the hydraulic main line, the hydraulic pump feeding the oil from the hydraulic tank into the hydraulic unit through the hydraulic main line to actuate the hydraulic unit;

a bypass path branching off from a discharge side of the hydraulic pump in the hydraulic main line to the hydraulic tank;

a flow rate control means provided in the bypass path to control a flow rate of the bypass path;

a pressure sensor provided in an inlet of the hydraulic unit in the hydraulic main line;

a control device to which a pressure detection value is input from the pressure sensor to control the flow rate control means based on the pressure detection value; and

a temperature sensor for detecting a temperature of the oil and inputting a temperature detection value to the control device,

wherein the oil is circulated in the bypass path while keeping a pump discharge pressure and the flow rate equal to or smaller than given specified values,

wherein the flow rate control means is a bypass valve that is configured to open or close the bypass path, and

wherein the control device is configured;

to circulate the oil in the bypass path while controlling the bypass valve via PWM control in order to keep an actuator power of the hydraulic pump equal to or smaller than a maximum value based on the pressure detection value and a set curve of an actuation power of the pressure and the flow rate of the hydraulic unit, when the temperature detection value is lower than a predetermined temperature; and

to perform control to stop circulating the oil in the bypass path, when the temperature detection value reaches the predetermined temperature.

9. A hydraulic system adapted to feed oil from a hydraulic tank into a hydraulic unit, the hydraulic system comprising:

a hydraulic main line for connecting the hydraulic tank and the hydraulic unit;

a hydraulic pump placed in the hydraulic main line, the hydraulic pump feeding the oil from the hydraulic tank into the hydraulic unit through the hydraulic main line to actuate the hydraulic unit;

a bypass path branching off from a discharge side of the hydraulic pump in the hydraulic main line to the hydraulic tank;

a flow rate control means provided in the bypass path to control a flow rate of the bypass path;

a pressure sensor provided in an inlet of the hydraulic unit in the hydraulic main line;

a control device to which a pressure detection value is input from the pressure sensor to control the flow rate control means based on the pressure detection value; and

a temperature sensor for detecting a temperature of the oil and inputting a temperature detection value to the control device,

wherein the oil is circulated in the bypass path while keeping a pump discharge pressure and the flow rate equal to or smaller than given specified values, and

wherein the control device is configured;

to circulate the oil in the bypass path while controlling the flow rate control means in order to keep an actuation power of the hydraulic pump equal to a maximum value based on the pressure detection value and a set curve of an actuation power of the pressure and the flow rate of the hydraulic unit, when the temperature detection value is lower than a predetermined temperature;

to perform control to stop circulating the oil in the bypass path, when the temperature detection value reaches the predetermined temperature, and

to confirm that there is no load in the hydraulic main line based on the pressure detection value from the pressure sensor before a startup of the hydraulic pump.

10. A hydraulic system adapted to feed oil from a hydraulic tank into a hydraulic unit, the hydraulic system comprising:

a hydraulic main line for connecting the hydraulic tank and the hydraulic unit;

a hydraulic pump placed in the hydraulic main line, the hydraulic pump feeding the oil from the hydraulic tank into the hydraulic unit through the hydraulic main line to actuate the hydraulic unit;

a bypass path branching off from a discharge side of the hydraulic pump in the hydraulic main line to the hydraulic tank;

a flow rate control means provided in the bypass path to control a flow rate of the bypass path;

a pressure sensor provided in an inlet of the hydraulic unit in the hydraulic main line;

a control device to which a pressure detection value is input from the pressure sensor to control the flow rate control means based on the pressure detection value; and

a temperature sensor for detecting a temperature of the oil and inputting a temperature detection value to the control device,

wherein the oil is circulated in the bypass path while keeping a pump discharge pressure and the flow rate equal to or smaller than given specified values,

wherein the flow rate control means is a bypass valve that opens or closes the bypass path, and

wherein the control device is configured;

to perform control in order to set the pressure detection value at a pressure value where a maximum value of an actuation power of the hydraulic pump is obtained based on a set curve of an actuation power of the pressure and the flow rate of the hydraulic unit, when the temperature detection value is lower than a predetermined temperature;

to perform control to stop circulating the oil in the bypass path, when the temperature detection value reaches the predetermined temperature, and

to confirm that there is no load in the hydraulic main line based on the pressure detection value from the pressure sensor before a startup of the hydraulic pump.

11. A hydraulic system adapted to feed oil from a hydraulic tank into a hydraulic unit, the hydraulic system comprising:

a hydraulic main line for connecting the hydraulic tank and the hydraulic unit;

a hydraulic pump placed in the hydraulic main line, the hydraulic pump feeding the oil from the hydraulic tank into the hydraulic unit through the hydraulic main line to actuate the hydraulic unit;

a bypass path branching off from a discharge side of the hydraulic pump in the hydraulic main line to the hydraulic tank;

a flow rate control means provided in the bypass path to control a flow rate of the bypass path;

a pressure sensor provided in an inlet of the hydraulic unit in the hydraulic main line;

a control device to which a pressure detection value is input from the pressure sensor to control the flow rate control means based on the pressure detection value; and

a temperature sensor for detecting a temperature of the oil and inputting a temperature detection value to the control device,

wherein the oil is circulated in the bypass path while keeping a pump discharge pressure and the flow rate equal to or smaller than given specified values,

wherein the flow rate control means is a bypass valve that is configured to open or close the bypass path, and

wherein the control device is configured;

to circulate the oil in the bypass path while controlling the bypass valve via PWM control in order to keep an actuator power of the hydraulic pump equal to or smaller than a maximum value based on the pressure detection value and a set curve of an actuation power of the pressure and the flow rate of the hydraulic unit, when the temperature detection value is lower than a predetermined temperature;

to perform control to stop circulating the oil in the bypass path, when the temperature detection value reaches the predetermined temperature, and

to confirm that there is no load in the hydraulic main line based on the pressure detection value from the pressure sensor before a startup of the hydraulic pump.