CN100571016C - A variable speed and constant frequency method and device for ocean current power generation based on hydraulic transmission - Google Patents

A variable speed and constant frequency method and device for ocean current power generation based on hydraulic transmission Download PDF

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CN100571016C
CN100571016C CNB2008101204833A CN200810120483A CN100571016C CN 100571016 C CN100571016 C CN 100571016C CN B2008101204833 A CNB2008101204833 A CN B2008101204833A CN 200810120483 A CN200810120483 A CN 200810120483A CN 100571016 C CN100571016 C CN 100571016C
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impeller
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main shaft
hydraulic pump
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李伟
马舜
林勇刚
刘宏伟
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Zhejiang University ZJU
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Abstract

本发明公开了一种基于液压传动的海流发电变速恒频方法及其装置。将叶轮的主轴和变量泵相连,变量泵输出的高压油接入蓄能器和变量马达,永磁同步发电机和变量马达相连后接电网;在叶轮主轴和发电机主轴分别安装转速传感器,控制器根据叶轮转速和海流流速计算变量泵的排量信号并输出,调节变量泵的排量以改变变量泵主轴上的反扭矩,从而改变叶轮的转速,实现变速运转。控制器根据发电机的转速和额定转速计算变量马达的排量信号并输出,调节变量马达的排量使变量马达的转速恒定,使发电机发出额定频率的电能,实现恒频运转。本发明使海流发电装置的变速运转和其能量输出更加平稳,受海流的冲击影响更小,没有变流设备,具有较高的效率。

Figure 200810120483

The invention discloses a variable-speed and constant-frequency method and device for ocean current power generation based on hydraulic transmission. Connect the main shaft of the impeller to the variable pump, the high pressure oil output by the variable pump is connected to the accumulator and the variable motor, the permanent magnet synchronous generator is connected to the variable motor and then connected to the power grid; the speed sensors are respectively installed on the main shaft of the impeller and the main shaft of the generator to control The controller calculates the displacement signal of the variable pump according to the speed of the impeller and the velocity of the sea current and outputs it, and adjusts the displacement of the variable pump to change the reaction torque on the main shaft of the variable pump, thereby changing the speed of the impeller to achieve variable speed operation. The controller calculates and outputs the displacement signal of the variable motor according to the rotational speed and rated rotational speed of the generator, and adjusts the displacement of the variable motor to keep the rotational speed of the variable motor constant, so that the generator can generate electric energy at the rated frequency to realize constant frequency operation. The invention makes the variable-speed operation and energy output of the ocean current power generation device more stable, is less affected by the impact of the ocean current, has no current conversion equipment, and has higher efficiency.

Figure 200810120483

Description

一种基于液压传动的海流发电变速恒频方法及其装置 A variable speed and constant frequency method and device for ocean current power generation based on hydraulic transmission

技术领域 technical field

本发明涉及发电系统的变速恒频方法及其装置,尤其是一种基于液压传动的海流发电变速恒频方法及其装置。The invention relates to a speed-variable and constant-frequency method of a power generation system and a device thereof, in particular to a hydraulic transmission-based ocean current power generation variable-speed and constant-frequency method and a device thereof.

背景技术 Background technique

水平轴式的海流发电装置是21世纪初开始进入研究领域的新型海流能开发利用装置,它基于贝兹能量捕获理论,通过叶轮捕获水流动能并将其转换为电能。类似于风力发电,当叶轮的转速随着水流速度变化时,可使叶轮捕获更多的海流能。当海流发电装置中的发电机和电网并联时,又要求发电机发出恒定频率的电能,即恒频运转。目前世界上所设计的水平轴式的海流发电装置其能量传递方式都为机械式传动,即叶轮通过齿轮箱带动发电机转动而发电,而齿轮箱的传动比是固定的,要使水平轴式的海流发电装置变速恒频运转可以运用风力发电领域中的变速恒频方法,主要有两种。一种方法是采用支持变速运转的双馈异步发电机,通过控制发电机使叶轮变速运转,从而发电机也随着叶轮变速运转,当发电机转速变化时,通过双馈异步发电机转子侧的变频装置的调节使得发电机发出的电能频率恒定。另一种方法是采用普通的同步发电机,在发电机和电网之间连接整流逆变控制器,通过整流逆变控制器的调节使叶轮变速运转,同时使得变速运转的发电机发出恒定频率的电能,然后并入电网。以上两种变速恒频方法都基于电气方式,都需要造价昂贵的变流设备,在能量传递过程中会造成15%以上的能量损失。在水平轴式的海流发电装置中,若采用电气式的变速恒频方法,由于发电机是叶轮经齿轮箱增速后带动发电的,发电机受海流的冲击影响较大,进而使叶轮的变速运转和海流发电装置的能量输出更不稳定。此外,其昂贵的发电机还要放置在水下,这给维修造成不便,变流设备的使用不仅造成能量的损失,还使得发电系统的结构庞大复杂,尤其使得电气系统复杂。The horizontal axis ocean current power generation device is a new type of ocean current energy development and utilization device that entered the research field at the beginning of the 21st century. It is based on Bezier's energy capture theory, which captures the kinetic energy of water through the impeller and converts it into electrical energy. Similar to wind power, when the speed of the impeller changes with the speed of the water flow, it can make the impeller capture more energy of the ocean current. When the generator in the ocean current power generation device is connected in parallel with the power grid, the generator is required to generate electric energy with a constant frequency, that is, to operate at a constant frequency. At present, the energy transmission mode of the horizontal-axis current power generation devices designed in the world is mechanical transmission, that is, the impeller drives the generator to rotate through the gearbox to generate electricity, and the transmission ratio of the gearbox is fixed. The variable speed and constant frequency operation of the ocean current power generation device can use the variable speed and constant frequency method in the field of wind power generation, and there are mainly two types. One method is to use a doubly-fed asynchronous generator that supports variable speed operation. By controlling the generator to make the impeller run at variable speed, the generator also operates with the variable speed of the impeller. When the generator speed changes, the rotor side of the doubly-fed asynchronous generator The adjustment of the frequency conversion device makes the frequency of the electric energy sent by the generator constant. Another method is to use an ordinary synchronous generator, connect a rectifier inverter controller between the generator and the power grid, and make the impeller run at variable speed through the adjustment of the rectifier inverter controller, and at the same time make the generator running at variable speed emit constant frequency Electric energy is then fed into the grid. Both of the above two variable speed and constant frequency methods are based on electrical methods, and both require expensive inverter equipment, which will cause more than 15% energy loss during the energy transfer process. In the horizontal axis type ocean current power generation device, if the electric variable speed and constant frequency method is adopted, since the generator is driven by the impeller to generate electricity after the gear box speeds up, the generator is greatly affected by the impact of the ocean current, and the variable speed of the impeller The energy output of operation and sea current power generation device is more unstable. In addition, its expensive generators have to be placed underwater, which makes maintenance inconvenient. The use of inverter equipment not only causes energy loss, but also makes the structure of the power generation system huge and complicated, especially the electrical system.

发明内容 Contents of the invention

本发明的目的在于提供一种基于液压传动的海流发电变速恒频方法及其装置,利用液压传动方式进行能量的转换,在液压能传递过程中通过对变量液压泵、变量液压马达的排量调节来实现海流发电装置的变速和恒频运转,提高海流发电装置的能量捕获率,使海流发电装置的变速运转和能量输出更加稳定。The purpose of the present invention is to provide a hydraulic transmission-based ocean current power generation variable speed constant frequency method and its device, which uses hydraulic transmission to convert energy, and adjusts the displacement of variable hydraulic pumps and variable hydraulic motors in the process of hydraulic energy transmission. To realize the variable speed and constant frequency operation of the ocean current power generation device, improve the energy capture rate of the ocean current power generation device, and make the variable speed operation and energy output of the ocean current power generation device more stable.

本发明解决其技术问题所采用的技术方案是:The technical solution adopted by the present invention to solve its technical problems is:

一、一种基于液压传动的海流发电变速恒频方法:1. A variable speed and constant frequency method for ocean current power generation based on hydraulic transmission:

1)将叶轮的机械能输入变量液压泵的主轴,将变量液压马达输出的机械能输入永磁同步发电机的主轴,在叶轮的主轴和永磁同步发电机的主轴上分别安装转速传感器,在叶轮的转动平面上安装流速传感器,存储控制程序的PLC控制器分别与叶轮转速传感器、发电机转速传感器、流速传感器、变量液压泵和变量液压马达电气连接;1) Input the mechanical energy of the impeller into the main shaft of the variable hydraulic pump, input the mechanical energy output by the variable hydraulic motor into the main shaft of the permanent magnet synchronous generator, and install speed sensors on the main shaft of the impeller and the main shaft of the permanent magnet synchronous generator respectively. A flow rate sensor is installed on the rotating plane, and the PLC controller storing the control program is electrically connected with the impeller speed sensor, the generator speed sensor, the flow rate sensor, the variable hydraulic pump and the variable hydraulic motor;

2)用流速传感器和叶轮转速传感器分别测量海流的流速v和叶轮的转速ny,输入PLC控制器,PLC控制器根据海流的流速v和叶轮的最佳叶尖速比值λopt计算出叶轮的最佳转速nopt,然后根据叶轮的最佳转速nopt和叶轮的转速ny由其内部的控制算法计算出变量液压泵的排量控制信号qp并输出,通过变量液压泵的变量机构调节其排量,进而改变变量液压泵主轴上的反扭矩,从而改变叶轮的转速,实现叶轮的变速运转;2) Use the flow velocity sensor and the impeller speed sensor to measure the flow velocity v of the sea current and the speed n y of the impeller respectively, and input them to the PLC controller. The PLC controller calculates the impeller speed according to the flow velocity v of the sea current and the optimal tip speed ratio λ opt of the impeller. Optimum rotational speed n opt , and then according to the optimum rotational speed n opt of the impeller and the rotational speed n y of the impeller, the displacement control signal q p of the variable hydraulic pump is calculated by its internal control algorithm and output, adjusted by the variable mechanism of the variable hydraulic pump Its displacement, and then change the reaction torque on the main shaft of the variable hydraulic pump, thereby changing the speed of the impeller, and realizing the variable speed operation of the impeller;

3)用发电机转速传感器测量永磁同步发电机的转速ng,输入PLC控制器,PLC控制器根据转速ng和永磁同步发电机的额定转速ngN由其内部控制算法计算出变量液压马达的排量控制信号qm并输出,通过变量液压马达的变量机构调节其排量,从而使变量液压马达的转速恒定在永磁同步发电机的额定转速ngN,进而使永磁同步发电机发出恒定频率的电能,实现永磁同步发电机的恒频运转。3) Use the generator speed sensor to measure the speed n g of the permanent magnet synchronous generator, and input it to the PLC controller. The PLC controller calculates the variable hydraulic pressure based on the speed n g and the rated speed n gN of the permanent magnet synchronous generator by its internal control algorithm. The displacement control signal q m of the motor is output, and its displacement is adjusted through the variable mechanism of the variable hydraulic motor, so that the speed of the variable hydraulic motor is constant at the rated speed n gN of the permanent magnet synchronous generator, and then the permanent magnet synchronous generator Generate constant frequency electric energy to realize constant frequency operation of permanent magnet synchronous generator.

二、一种基于液压传动的海流发电变速恒频装置:2. A variable speed and constant frequency device for ocean current power generation based on hydraulic transmission:

将叶轮的主轴和变量液压泵的主轴相连,变量液压泵通过油管与滤油器和油箱连接,滤油器的出口连接安全阀,变量液压泵输出的高压油经滤油器和单向阀接入蓄能器和变量液压马达,在蓄能器的入口安装截止阀,变量液压马达的主轴直接和永磁同步发电机的主轴相连,永磁同步发电机直接和电网相连;PLC控制器分别与叶轮转速传感器、发电机转速传感器、流速传感器、变量液压泵和变量液压马达电气连接。Connect the main shaft of the impeller to the main shaft of the variable hydraulic pump. The variable hydraulic pump is connected to the oil filter and the oil tank through the oil pipe. The outlet of the oil filter is connected to the safety valve. The high pressure oil output by the variable hydraulic pump is connected to the The accumulator and the variable hydraulic motor are installed, and a cut-off valve is installed at the entrance of the accumulator. The main shaft of the variable hydraulic motor is directly connected with the main shaft of the permanent magnet synchronous generator, and the permanent magnet synchronous generator is directly connected with the power grid; the PLC controller is connected with the power grid respectively. The impeller speed sensor, generator speed sensor, flow rate sensor, variable hydraulic pump and variable hydraulic motor are electrically connected.

本发明与背景技术相比具有的有益效果是:The beneficial effect that the present invention has compared with background technology is:

1.相比基于电气式的变速恒频方法,基于液压传动的变速恒频方法使海流发电装置的变速运转和其能量输出传递更加平稳,受海流的冲击影响更小,尤其适用于水平轴式的海流发电装置。1. Compared with the variable speed and constant frequency method based on the electric type, the variable speed and constant frequency method based on the hydraulic transmission makes the variable speed operation and energy output transmission of the ocean current power generation device more stable, and is less affected by the impact of the ocean current, especially suitable for the horizontal shaft type ocean current power generation device.

2.采用变量液压泵和变量液压马达的排量调节来实现海流发电装置的变速恒频运转,简单可靠,能量在传递过程中损失较少,使发电系统具有较高的效率。2. The displacement adjustment of the variable hydraulic pump and the variable hydraulic motor is used to realize the variable speed and constant frequency operation of the ocean current power generation device. It is simple and reliable, and the energy is less lost during the transmission process, so that the power generation system has higher efficiency.

3.本发明方法所需的装置简单,发电机采用普通的永磁同步发电机,且可放置在海平面上,其输出电能可直接并入电网,省去了变流设备,使海流发电装置的电气系统简单可靠。3. The required device of the inventive method is simple, and the generator adopts a common permanent magnet synchronous generator, and can be placed on sea level, and its output electric energy can be directly incorporated into the power grid, eliminating the need for converter equipment, so that the ocean current power generation device The electrical system is simple and reliable.

附图说明 Description of drawings

图1是本发明的液压原理图。Fig. 1 is the hydraulic principle diagram of the present invention.

图2是PLC控制器的工作原理图。Figure 2 is a schematic diagram of the working principle of the PLC controller.

图3是叶轮的叶尖速比值和叶轮的能量捕获率之间的关系曲线。Fig. 3 is a relationship curve between the tip speed ratio of the impeller and the energy capture rate of the impeller.

图中:1、叶轮,2、叶轮转速传感器,3、流速传感器,4、变量液压泵,5、滤油器,6、安全阀,7、单向阀,8、截止阀,9、蓄能器,10、变量液压马达,11、油箱,12、发电机转速传感器,13、永磁同步发电机,14、电网,15、PLC控制器In the figure: 1. impeller, 2. impeller speed sensor, 3. flow rate sensor, 4. variable hydraulic pump, 5. oil filter, 6. safety valve, 7. one-way valve, 8. stop valve, 9. energy storage Device, 10. Variable hydraulic motor, 11. Fuel tank, 12. Generator speed sensor, 13. Permanent magnet synchronous generator, 14. Power grid, 15. PLC controller

v-流速传感器输出的海流流速信号,λopt-叶轮的最佳叶尖速比值v - the sea current velocity signal output by the velocity sensor, λ opt - the optimum tip speed ratio of the impeller

nopt-叶轮的最佳转速信号,ny-叶轮转速传感器输出的叶轮转速信号n opt - the optimum rotational speed signal of the impeller, n y - the impeller rotational speed signal output by the impeller rotational speed sensor

nye-叶轮的转速偏差信号,qp-变量液压泵的排量控制信号n ye - the speed deviation signal of the impeller, q p - the displacement control signal of the variable hydraulic pump

ngN-永磁同步发电机的额定转速值,ng-发电机转速传感器输出的发电机转速信号n gN - the rated speed value of the permanent magnet synchronous generator, n g - the generator speed signal output by the generator speed sensor

nge-发电机的转速偏差信号,qm-变量液压马达的排量控制信号n ge - the speed deviation signal of the generator, q m - the displacement control signal of the variable hydraulic motor

CP-叶轮的能量捕获率,CPmax-叶轮的最大能量捕获率C P - the energy capture rate of the impeller, C Pmax - the maximum energy capture rate of the impeller

λ-叶轮的叶尖速比值λ - the tip speed ratio of the impeller

具体实施方式 Detailed ways

下面结合附图和实施例对本发明作进一步说明。The present invention will be further described below in conjunction with drawings and embodiments.

如图1、图2所示,本发明将叶轮1的主轴和变量液压泵4的主轴相连,变量液压泵4通过油管与滤油器5和油箱11连接,滤油器5的出口连接安全阀6,变量液压泵4输出的高压油经滤油器5和单向阀7接入蓄能器9和变量液压马达10,在蓄能器9的入口安装截止阀8,变量液压马达10的主轴直接和永磁同步发电机13的主轴相连,永磁同步发电机13直接和电网14相连;在叶轮1的主轴和永磁同步发电机13的主轴上分别安装转速传感器2、12,在叶轮1的转动平面上安装流速传感器3,PLC控制器15分别与叶轮转速传感器2、发电机转速传感器12、流速传感器3、变量液压泵4和变量液压马达10电气连接。As shown in Figure 1 and Figure 2, the present invention connects the main shaft of the impeller 1 with the main shaft of the variable hydraulic pump 4, the variable hydraulic pump 4 is connected with the oil filter 5 and the oil tank 11 through the oil pipe, and the outlet of the oil filter 5 is connected with the safety valve 6. The high-pressure oil output by the variable hydraulic pump 4 is connected to the accumulator 9 and the variable hydraulic motor 10 through the oil filter 5 and the one-way valve 7. A cut-off valve 8 is installed at the entrance of the accumulator 9, and the main shaft of the variable hydraulic motor 10 Directly link to each other with the main shaft of permanent magnet synchronous generator 13, and permanent magnet synchronous generator 13 directly links to each other with power grid 14; On the main shaft of impeller 1 and the main shaft of permanent magnet synchronous generator 13, rotational speed sensor 2,12 are installed respectively, on the main shaft of impeller 1 A flow velocity sensor 3 is installed on the rotation plane, and the PLC controller 15 is electrically connected with the impeller velocity sensor 2, the generator velocity sensor 12, the flow velocity sensor 3, the variable hydraulic pump 4 and the variable hydraulic motor 10 respectively.

如图1、图2所示,本发明用流速传感器3和叶轮转速传感器2分别测量海流的流速v和叶轮1的转速ny,输入PLC控制器15,PLC控制器15根据海流的流速v和叶轮的最佳叶尖速比值λopt计算出叶轮的最佳转速nopt,然后根据叶轮的最佳转速nopt和叶轮的转速ny由其内部的控制算法计算出变量液压泵4的排量控制信号qp并输出,通过变量液压泵4的变量机构调节其排量,进而改变变量液压泵4主轴上的反扭矩,从而改变叶轮1的转速,实现叶轮1的变速运转。As shown in Fig. 1 and Fig. 2, the present invention uses flow velocity sensor 3 and impeller rotational speed sensor 2 to measure respectively the flow velocity v of ocean current and the rotational speed n y of impeller 1, input PLC controller 15, PLC controller 15 according to the flow velocity v of ocean current and The optimal tip speed ratio λ opt of the impeller calculates the optimal rotational speed n opt of the impeller, and then calculates the displacement of the variable hydraulic pump 4 by its internal control algorithm based on the optimal rotational speed n opt of the impeller and the rotational speed n y of the impeller The control signal qp is output, and the displacement of the variable hydraulic pump 4 is adjusted through the variable mechanism, thereby changing the counter torque on the main shaft of the variable hydraulic pump 4, thereby changing the speed of the impeller 1, and realizing the variable speed operation of the impeller 1.

用发电机转速传感器12测量永磁同步发电机13的转速ng,输入PLC控制器15,PLC控制器15根据转速ng和永磁同步发电机13的额定转速ngN由其内部控制算法计算出变量液压马达10的排量控制信号qm并输出,通过变量液压马达10的变量机构调节其排量,从而使变量液压马达10的转速恒定在永磁同步发电机13的额定转速ngN,进而使永磁同步发电机13发出恒定频率的电能,实现永磁同步发电机13的恒频运转。Measure the rotational speed n g of the permanent magnet synchronous generator 13 with the generator rotational speed sensor 12, and input it to the PLC controller 15, and the PLC controller 15 calculates by its internal control algorithm according to the rotational speed n g and the rated rotational speed n gN of the permanent magnet synchronous generator 13 Output the displacement control signal q m of the variable hydraulic motor 10 and output it, adjust the displacement through the variable mechanism of the variable hydraulic motor 10, so that the speed of the variable hydraulic motor 10 is constant at the rated speed n gN of the permanent magnet synchronous generator 13, Furthermore, the permanent magnet synchronous generator 13 can generate electric energy with a constant frequency, so as to realize the constant frequency operation of the permanent magnet synchronous generator 13 .

本发明的原理如下:Principle of the present invention is as follows:

如图1所示,水平轴式的叶轮1在海流的流动冲击下产生升力而转动,捕获海流能并转换成机械能。叶轮直接带动变量液压泵4转动,将机械能输入至液压传动系统,变量液压泵从油箱吸入低压油,从其输出口输出具有一定压力和流量的液压油。变量液压泵4输出的高压油经过滤油器5和单向阀7部分流入蓄能器9中存储,部分流入变量液压马达10使液压马达主轴转动,从而直接带动永磁同步发电机13运转,将液压传动系统的液压能转换成机械能,发电机再将机械能转换成电能输出至电网。滤油器5的出口并联安全阀6,限制系统压力过高。滤油器5出口的单向阀7可防止蓄能器9和液压马达10的油液流向液压泵。蓄能器9入口安装的截止阀8在系统安装和维修时能封闭液压油液。As shown in FIG. 1 , the impeller 1 of the horizontal axis type generates lift under the flow impact of the ocean current and rotates, captures the energy of the ocean current and converts it into mechanical energy. The impeller directly drives the variable hydraulic pump 4 to rotate, and inputs mechanical energy to the hydraulic transmission system. The variable hydraulic pump sucks low-pressure oil from the oil tank, and outputs hydraulic oil with a certain pressure and flow rate from its output port. The high-pressure oil output by the variable hydraulic pump 4 flows into the accumulator 9 through the oil filter 5 and the one-way valve 7 for storage, and partly flows into the variable hydraulic motor 10 to rotate the main shaft of the hydraulic motor, thereby directly driving the permanent magnet synchronous generator 13 to run. The hydraulic energy of the hydraulic transmission system is converted into mechanical energy, and the generator converts the mechanical energy into electrical energy and outputs it to the grid. The outlet of the oil filter 5 is connected in parallel with the safety valve 6 to limit the excessive pressure of the system. The one-way valve 7 at the outlet of the oil filter 5 can prevent the oil from the accumulator 9 and the hydraulic motor 10 from flowing to the hydraulic pump. The cut-off valve 8 installed at the inlet of the accumulator 9 can seal off the hydraulic fluid during system installation and maintenance.

叶轮的叶尖速比值λ=2πnyR/60v,其中ny为叶轮的转速,R为叶轮的半径,v为海流的流速。当叶片的安装角固定时,叶轮的能量捕获率CP和叶轮的叶尖速比值λ(叶轮叶尖的线速度和海流流速之比)之间存在一种非线性的关系,如图3所示,当叶尖速比λ等于最佳的叶尖速比λopt时,叶轮的能量捕获率CP可取到最大值CPmax,此时叶轮可以最大地捕获海流能。所以当海流的流速在额定流速以下变化时,改变叶轮的转速,使叶轮保持最佳叶尖速比λopt运转,就可以使叶轮的能量捕获率CP保持最大,从而最大地捕获海流能。而当海流的流速在额定流速以上变化时,希望叶轮捕获的功率不随流速的变化而变化,保持额定的捕获功率,这时同样可以通过调节叶轮的转速改变叶尖速比λ,使叶轮的能量捕获率Cp变化从而使叶轮的捕获功率恒定在额定值。The tip speed ratio of the impeller λ=2πn y R/60v, where n y is the rotational speed of the impeller, R is the radius of the impeller, and v is the velocity of the sea current. When the installation angle of the blade is fixed, there is a nonlinear relationship between the energy capture rate C P of the impeller and the tip speed ratio λ of the impeller (the ratio of the linear velocity of the impeller tip to the velocity of the sea current), as shown in Figure 3 It shows that when the tip speed ratio λ is equal to the optimal tip speed ratio λ opt , the energy capture rate C P of the impeller can take the maximum value C Pmax , at this time the impeller can capture the ocean current energy to the maximum. Therefore, when the flow velocity of the sea current changes below the rated flow velocity, changing the speed of the impeller to keep the impeller running at the optimum tip speed ratio λ opt can keep the energy capture rate C P of the impeller at the maximum, thereby maximizing the capture of sea current energy. When the flow velocity of the sea current changes above the rated flow velocity, it is hoped that the power captured by the impeller will not change with the change of the flow velocity, and the rated capture power will be maintained. At this time, the tip speed ratio λ can also be changed by adjusting the speed of the impeller to make the energy of the impeller The capture rate Cp is varied so that the capture power of the impeller remains constant at the rated value.

如图1、2所示,在叶轮1的主轴和永磁同步发电机13的主轴上分别安装转速传感器2、12,在叶轮1的转动平面上安装流速传感器3,添加一个存储控制程序的PLC控制器15。用流速传感器测量海流的流速信号v,输入PLC控制器,PLC控制器根据叶轮的最佳叶尖速比值λopt和海流的流速信号v计算出叶轮的最佳转速信号nopt,其中叶轮运转的最佳叶尖速比值λopt为存储在PLC控制器中的常数,该计算过程由存储在PLC控制器中的叶轮最佳转速计算程序完成。用叶轮转速传感器测量叶轮的转速ny输入至PLC控制器,PLC控制器根据叶轮的最佳转速信号nopt和叶轮的转速ny计算出叶轮的转速偏差信号nye,然后由PLC控制器内部存储的数字PID控制算法计算出变量液压泵的排量控制信号qp,并由PLC控制器输出,通过变量液压泵的变量机构调节变量泵的排量。而变量液压泵主轴上的反扭矩Tp=ppqp/2π,其中pp为泵的出口压力,由系统的负载决定,而系统的负载可视为不变,qp为变量液压泵的排量,故调节变量液压泵的排量qp就可以改变变量液压泵主轴上的反扭矩Tp,进而间接地改变叶轮的转速,实现叶轮的变速运转。以上通过调节液压泵的排量来控制叶轮的转速只对海流流速的低频分量响应,对流速的高频分量并不响应,流速高频分量引起的能量波动通过蓄能器来缓和。当流速在短时间内增大时,蓄能器把多余的能量储存起来,流速减小时,蓄能器把能量释放出来,使功率输出达到理想的状态。As shown in Figures 1 and 2, speed sensors 2 and 12 are respectively installed on the main shaft of the impeller 1 and the main shaft of the permanent magnet synchronous generator 13, and a flow sensor 3 is installed on the rotation plane of the impeller 1, and a PLC for storing control programs is added controller 15. Use the velocity sensor to measure the flow velocity signal v of the sea current and input it to the PLC controller. The PLC controller calculates the optimum speed signal n opt of the impeller according to the optimal blade tip speed ratio λ opt of the impeller and the flow velocity signal v of the sea current. The optimal tip speed ratio λopt is a constant stored in the PLC controller, and the calculation process is completed by the calculation program of the optimal impeller speed stored in the PLC controller. Use the impeller speed sensor to measure the speed n y of the impeller and input it to the PLC controller. The PLC controller calculates the speed deviation signal n ye of the impeller according to the optimal speed signal n opt of the impeller and the speed n y of the impeller, and then the internal The stored digital PID control algorithm calculates the displacement control signal q p of the variable hydraulic pump, and outputs it from the PLC controller, and adjusts the displacement of the variable pump through the variable mechanism of the variable hydraulic pump. And the reaction torque T p on the main shaft of the variable hydraulic pump = p p q p /2π, where p p is the outlet pressure of the pump, which is determined by the load of the system, and the load of the system can be regarded as constant, and q p is the variable hydraulic pump Therefore, adjusting the displacement q p of the variable hydraulic pump can change the reaction torque T p on the main shaft of the variable hydraulic pump, and then indirectly change the speed of the impeller to realize the variable speed operation of the impeller. The speed of the impeller controlled by adjusting the displacement of the hydraulic pump above only responds to the low-frequency component of the sea current velocity, and does not respond to the high-frequency component of the flow velocity. The energy fluctuation caused by the high-frequency component of the flow velocity is alleviated by the accumulator. When the flow rate increases in a short time, the accumulator stores the excess energy, and when the flow rate decreases, the accumulator releases the energy to make the power output reach the ideal state.

当永磁同步发电机和电网并联时,要求永磁同步发电机发出的电能频率和电网的频率一致,这就要求同步发电机以其额定转速运转。如图1、2所示,本发明方法中,用发电机转速传感器测量发电机的转速ng,输入PLC控制器,PLC控制器根据其内部存储的永磁同步发电机的额定转速值ngN和输入的发电机转速ng计算出发电机的转速偏差信号nge,并根据该偏差信号nge由PLC控制器内部存储的数字PID控制算法计算出变量液压马达的排量控制信号qm,并从PLC控制器输出,通过变量液压马达的变量机构调节变量液压马达的排量。而变量液压马达的转速nm=60QmηV/qm,其中Qm为流入液压马达的油液流量,随着叶轮捕获功率的大小而变化,ηV为液压马达的容积效率,可视为常量,qm为液压马达的排量,故当流入液压马达的油液流量Qm变化时,通过调节变量液压马达的排量qm就可以使得变量液压马达的转速nm恒定,保持为永磁同步发电机的额定转速值ngN,进而使永磁同步发电机发出恒定频率的电能,实现永磁同步发电机的恒频运转。When the permanent magnet synchronous generator is connected in parallel with the grid, the frequency of the electric energy generated by the permanent magnet synchronous generator is required to be consistent with the frequency of the grid, which requires the synchronous generator to run at its rated speed. As shown in Figures 1 and 2, in the method of the present invention, the rotational speed n g of the generator is measured by the generator rotational speed sensor, which is input to the PLC controller, and the PLC controller is based on the rated rotational speed value n gN of the permanent magnet synchronous generator stored inside it. Calculate the generator speed deviation signal n ge with the input generator speed n g , and calculate the displacement control signal q m of the variable hydraulic motor by the digital PID control algorithm stored in the PLC controller according to the deviation signal n ge , and From the output of the PLC controller, the displacement of the variable hydraulic motor is adjusted through the variable mechanism of the variable hydraulic motor. And the speed of the variable hydraulic motor n m =60Q m η V /q m , where Q m is the flow of oil flowing into the hydraulic motor, which changes with the power captured by the impeller, and η V is the volumetric efficiency of the hydraulic motor, which can be seen is a constant, and q m is the displacement of the hydraulic motor, so when the oil flow Q m flowing into the hydraulic motor changes, the speed n m of the variable hydraulic motor can be kept constant by adjusting the displacement q m of the variable hydraulic motor, which is kept as The rated rotational speed value n gN of the permanent magnet synchronous generator further enables the permanent magnet synchronous generator to generate electric energy with a constant frequency, and realizes the constant frequency operation of the permanent magnet synchronous generator.

Claims (2)

1, a kind of based on hydraulicdriven current power generation speed-changing constant frequency method, it is characterized in that:
1) with the main shaft of the mechanical energy input variable hydraulic pump of impeller, the hydraulic oil of volume adjustable hydraulic pump output is inserted accumulator and variable hydraulic motor through oil filter and unidirectional valve, thereby driving variable hydraulic motor rotates, again the mechanical energy of variable hydraulic motor output is imported the main shaft of magneto alternator, on the main shaft of the main shaft of impeller and magneto alternator, speed probe is installed respectively, on the rotational plane of impeller, flow sensor is installed, the PLC controller of storage control program respectively with the wheel speed transducer, the generator speed transducer, flow sensor, volume adjustable hydraulic pump and variable hydraulic motor are electrically connected;
2) measure the flow velocity v of ocean current and the rotation speed n of impeller respectively with flow sensor and wheel speed transducer y, input PLC controller, the PLC controller is according to the flow velocity v of ocean current and the best tip speed ratio value λ of impeller OptCalculate the optimum speed n of impeller Opt, the best tip speed ratio value λ of impeller wherein OptFor being stored in the constant in the PLC controller, then according to the optimum speed n of impeller OptRotation speed n with impeller yCalculate the discharge capacity control signal q of volume adjustable hydraulic pump by its inner control algolithm pAnd output, regulate its discharge capacity by the stroking mechanism of volume adjustable hydraulic pump, and then change the reaction torque on the volume adjustable hydraulic pump main shaft, thereby change the rotating speed of impeller, realize the changed speed operation of impeller;
3) rotation speed n of usefulness generator speed sensor measurement magneto alternator g, input PLC controller, the PLC controller is according to rotation speed n gRated speed n with magneto alternator GNGo out the discharge capacity control signal q of variable hydraulic motor by its internal control algorithm computation mAnd output, regulate its discharge capacity by the stroking mechanism of variable hydraulic motor, thereby make the rated speed n of the invariablenes turning speed of variable hydraulic motor at magneto alternator GN, and then make magneto alternator send the electric energy of constant frequency, realize the constant frequency running of magneto alternator.
2, be used for the described a kind of device of claim 1 based on hydraulicdriven current power generation speed-changing constant frequency method, it is characterized in that: the main shaft of impeller (1) and the main shaft of volume adjustable hydraulic pump (4) are linked to each other, volume adjustable hydraulic pump (4) is connected with fuel tank (11) with oil filter (5) by oil pipe, the outlet attachment security valve (6) of oil filter (5), the hydraulic oil of volume adjustable hydraulic pump (4) output inserts accumulator (9) and variable hydraulic motor (10) through oil filter (5) and unidirectional valve (7), inlet at accumulator (9) is installed break valve (8), the main shaft of variable hydraulic motor (10) directly links to each other with the main shaft of magneto alternator (13), and magneto alternator (13) directly links to each other with electrical network (14); PLC controller (15) is electrically connected with wheel speed transducer (2), generator speed transducer (12), flow sensor (3), volume adjustable hydraulic pump (4) and variable hydraulic motor (10) respectively.
CNB2008101204833A 2008-09-08 2008-09-08 A variable speed and constant frequency method and device for ocean current power generation based on hydraulic transmission Expired - Fee Related CN100571016C (en)

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