CN106130421A - A kind of inertia control system based on double-fed fan motor unit and method - Google Patents

Abstract

A kind of inertia control method based on double-fed fan motor unit, including mains frequency detection module, inertia response module；Mains frequency detection module is for quickly mains frequency being detected with high-precision；Inertia response module, the mains frequency according to detecting is changed to foundation, controls torque and the rotating speed of Wind turbines respectively；Realize simulating the synchrodrive inertia response characteristic of certain fixing inertia time constant, send torque instruction to current transformer；Rotary speed instruction carries out generator operation rotating speed control for master control, and rotating speed controls the clipping parameter of ring and can adjust in real time according to the operating condition of mains frequency and unit.And a kind of inertia control method based on double-fed fan motor unit is provided.The present invention effectively solves wind-powered electricity generation high permeability lower frequency stability problem.

Description

A kind of inertia control system based on double-fed fan motor unit and method

Technical field

The present invention relates to technical field of wind power, a kind of double-fed fan motor unit participates in the control system of mains frequency regulation System and method.

Background technology

Along with wind-powered electricity generation ratio in power supply architecture constantly increases, its impact running power system safety and stability is day by day Significantly.Some areas Wind Power Development progressively manifests with the contradiction of system safety operation, abandons wind phenomenon and constantly occurs, wind electricity digestion is The key issue that Wind Power In China develops in a healthy way is affected through becoming.So, due to wind-powered electricity generation proportion continuous in power system Soaring and the extensive of variable speed constant frequency wind power technology is applied, and wind-electricity integration runs to power system stability and brings new challenge, The problems such as the regulation of systems face such as Control of Voltage, frequency and the quality of power supply.Thus, make Wind turbines provide complementary for system Service such as frequency regulation, idle control etc. and become the inexorable trend of Wind Power Development.

Generally, power plant includes inertial response, primary frequency modulation and frequency modulation frequency modulation, and 3 kinds of frequencies for the response of system frequency Have complementary functions between rate control form, complement each other.

Inertia response has short-term to inject the ability of active power to electrical network, until system primary frequency modulation controls to activate.Tradition Electromotor inertia responding ability is relevant with the physical phenomenon of its physical quality block size, synchronous motor, after electromotor type selecting determines, Rotary inertia is steady state value and cannot change.

Its rotor of double-fed wind power generator group is connected with electrical network by inverter, causes rotor speed and system frequency solution Coupling, does not contribute the inertia of system, it is impossible to provides for a FREQUENCY CONTROL and supports.Owing to variable-speed wind-power unit have employed electric power Electronic converter, it is achieved that mechanical output and the uneoupled control of system electromagnetic power, the most therefore loses quickly having frequency Effect response, causes its rotation function to the inertia of whole system almost without contribution.

Wind turbines kinetic energy includes the kinetic energy of blade, gear-box, electromotor.Turbines vane inertia being used to far above electromotor Amount, but electromotor has higher rotating speed, so storing substantial amounts of kinetic energy in Wind turbines.

Summary of the invention

In order to solve the deficiency of the mains frequency less stable that existing wind-electricity integration mode is brought, the invention provides one Plant inertia control system based on double-fed fan motor unit and the method effectively solving wind-powered electricity generation high permeability lower frequency stability problem.

The technical solution adopted for the present invention to solve the technical problems is:

A kind of inertia control system based on double-fed fan motor unit, including:

Mains frequency detection module, for quickly detecting mains frequency with high-precision；

Inertia response module, for being changed to foundation according to the mains frequency detected, controls Wind turbines respectively Torque and rotating speed；

In described inertia response module, simulate the synchrodrive inertia response characteristic of certain fixing inertia time constant, will Torque instruction sends current transformer to；Rotary speed instruction carries out generator operation rotating speed control for master control, and rotating speed controls the amplitude limit of ring Parameter can adjust in real time according to the operating condition of mains frequency and unit.

A kind of inertia control method based on double-fed fan motor unit, described control method comprises the following steps:

1) frequency collection: with the Wind turbines port of export for measuring point, gathers the frequency of line voltage, and is filtered place Reason；

2) direct torque: according to certain default inertia time constant, detect the real-time rotating speed of generating set and obtain frequency The frequency that detection module transmits, calculates the additional torque of inertia response, and Conventional torque controls turning of ring according to rate of change Square set-point sends current transformer to after being added with additional torque；

3) rotating speed controls: control to calculate turn according to current rotating speed, relative speed variation, the inertia time constant of predetermined analog Speed initial target value, carries out amplitude limiting processing to rotating speed initial target value, and the rotating speed before controlling with reference to electromotor inertia carries out unit The judgement of running status, and clipping parameter is set according to rotating speed and mains frequency.

Further, described step 2) in, my computing formula of additional torque is as follows:

$\mathrm{\Δ}T=K\frac{df}{dt}$

Wherein, Δ T is additional torque, and K is additional torque design factor, by unit rated capacity, rated frequency and generating Machine rotary speed parameter determines, f is mains frequency.

Further, described step 3) in, rotating speed initial target value ω_t, computing formula is as follows:

$\frac{1}{2}{{\mathrm{J\ω}}_t}^2=K\frac{df}{dt}\×{\mathrm{\ω}}_g\×T+\frac{1}{2}{{\mathrm{J\ω}}_g}^2$

Wherein, ω_gFor the current rotating speed of electromotor；K is additional torque design factor；T is that rotating speed controls the cycle；J is wind-force Generating set inertia value；ω_tFor rotating speed initial target value；For relative speed variation.

The technology of the present invention is contemplated that: the rotor of double-fed wind power generator group is connected with electrical network by inverter, causes and turns Rotor speed decouples with system frequency, not contributes the inertia of system, it is impossible to provides for a FREQUENCY CONTROL and supports.But, wind Group of motors kinetic energy includes the kinetic energy of blade, gear-box, electromotor.Turbines vane inertia is far above the inertia of electromotor, but sends out Motor has higher rotating speed, so Wind turbines has substantial amounts of kinetic energy.Become owing to variable-speed wind-power unit have employed power electronics Parallel operation, Wind turbines can quickly control to respond effect, therefore consider the Inertia Characteristics of simulation conventional synchronous machine.

The mains frequency measured, with the Wind turbines port of export as test point, is carried out low by mains frequency detection and acquisition module Pass filter processes, and carries out torque according to the rate of change (increase or reduce) of mains frequency and rotating speed controls.

First, direct torque calculates according to certain the inertia time constant preset, the real-time rotating speed of generating set, frequency change rate Go out inertia response additional torque, and the torque set-point that Conventional torque is controlled ring be added with additional torque after send unsteady flow to Device；

Secondly, rotating speed controls to calculate rotating speed according to current rotating speed, relative speed variation, the inertia time constant of predetermined analog Desired value.

After carrying out amplitude limit finally, for rotating speed desired value given herein above, then the rotating speed carrying out electromotor controls.For machine The amplitude limit value of group needs the rotating speed before controlling according to electromotor inertia to carry out the judgement of operating states of the units, and according to rotating speed and electricity Net frequency configuration clipping parameter.

Beneficial effects of the present invention is mainly manifested in: 1. can quickly provide frequency to support according to mains frequency change； 2. the Main Basis supported due to frequency is frequency change rate, so inertia response frequency support effect is notable；3. have employed and turn The method that square and rotating speed control simultaneously, it is achieved that maximal power tracing controls ring and controls coupling between ring with inertia response；4、 The method using rotating speed clipping parameter real-time change, it is ensured that unit is in the smooth control of different traffic coverage rotating speeds.

Fig. 1 is direct torque schematic diagram.

Fig. 2 is rotating speed control and rotating speed amplitude limit schematic diagram.

Detailed description of the invention

The invention will be further described below in conjunction with the accompanying drawings.

Reference Fig. 1～Fig. 2, a kind of inertia control system based on double-fed fan motor unit, including:

Mains frequency detection module, for quickly detecting mains frequency with high-precision；

Inertia response module, for being changed to foundation according to the mains frequency detected, controls Wind turbines respectively Torque and rotating speed；

In described inertia response module, simulate the synchrodrive inertia response characteristic of certain fixing inertia time constant, will Torque instruction sends current transformer to；Rotary speed instruction carries out generator operation rotating speed control for master control, and rotating speed controls the amplitude limit of ring Parameter can adjust in real time according to the operating condition of mains frequency and unit.

A kind of inertia control method based on double-fed fan motor unit, described control method comprises the following steps:

1) frequency collection: with the Wind turbines port of export for measuring point, gathers the frequency of line voltage, and is filtered place Reason.

2) direct torque: according to certain default inertia time constant, detect the real-time rotating speed of generating set and obtain frequency The frequency that detection module transmits, calculates the additional torque of inertia response according to rate of change, and computing formula is as follows:

$\mathrm{\Δ}T=K\frac{df}{dt}$

Wherein, Δ T is additional torque, and K is additional torque design factor, by unit rated capacity, rated frequency, electromotor The parameters such as rotating speed determine, f is mains frequency.

Control Conventional torque to send current transformer to after the torque set-point of ring is added with additional torque.

3) rotating speed controls: calculate at the beginning of rotating speed according to current rotating speed, relative speed variation, the inertia time constant of predetermined analog Beginning desired value ω_t, computing formula is as follows:

$\frac{1}{2}{{\mathrm{J\ω}}_t}^2=K\frac{df}{dt}\×{\mathrm{\ω}}_g\×T+\frac{1}{2}{{\mathrm{J\ω}}_g}^2$

Wherein, ω_gFor the current rotating speed of electromotor；K is additional torque design factor；T is that rotating speed controls the cycle；J is wind-force Generating set inertia value；ω_tFor rotating speed initial target value；For relative speed variation.

Rotating speed initial target value carries out amplitude limiting processing, and the rotating speed before controlling with reference to electromotor inertia carries out unit operation shape The judgement of state, and according to rotating speed and mains frequency by Wind turbines master control system parameter assignment is carried out clipping parameter setting.

Claims (4)

1. an inertia control system based on double-fed fan motor unit, it is characterised in that: described inertia control system includes:

Mains frequency detection module, is used for detecting mains frequency；

Inertia response module, for being changed to foundation according to the mains frequency detected, controls turning of Wind turbines respectively Square and rotating speed；

In described inertia response module, simulate the synchrodrive inertia response characteristic of certain fixing inertia time constant, by torque Instruction sends current transformer to；Rotary speed instruction carries out generator operation rotating speed control for master control, and rotating speed controls the clipping parameter of ring Can adjust in real time according to the operating condition of mains frequency and unit.

2. one kind uses the inertia controlling party that inertia control system based on double-fed fan motor unit as claimed in claim 1 realizes Method, it is characterised in that: described control method comprises the following steps:

1) frequency collection: with the Wind turbines port of export for measuring point, gather the frequency of line voltage, and carry out Filtering Processing；

2) direct torque: according to certain default inertia time constant, detect the real-time rotating speed of generating set and obtain frequency detecting The frequency that module transmits, calculates the additional torque of inertia response according to rate of change, and Conventional torque is controlled the torque of ring to Definite value sends current transformer to after being added with additional torque；

3) rotating speed controls: control to calculate at the beginning of rotating speed according to current rotating speed, relative speed variation, the inertia time constant of predetermined analog Beginning desired value, carries out amplitude limiting processing to rotating speed initial target value, and the rotating speed before controlling with reference to electromotor inertia carries out unit operation The judgement of state, and clipping parameter is set according to rotating speed and mains frequency.

3. inertia control method as claimed in claim 2, it is characterised in that: described step 2) in, additional torque computing formula As follows:

$\mathrm{\Δ}T=K\frac{df}{dt}$

Wherein, Δ T is additional torque, and K is additional torque design factor, unit rated capacity, rated frequency and electromotor turn Speed parameter determines, f is mains frequency.

4. inertia control method as claimed in claim 2, it is characterised in that: described step 3) in, rotating speed initial target value ω_t, Computing formula is as follows:

$\frac{1}{2}{{\mathrm{J\ω}}_t}^2=K\frac{df}{dt}\×{\mathrm{\ω}}_g\×T+\frac{1}{2}{{\mathrm{J\ω}}_g}^2$

Wherein, ω_gFor the current rotating speed of electromotor；K is additional torque design factor；T is that rotating speed controls the cycle；J is wind-driven generator Group inertia value；ω_tFor rotating speed initial target value；For relative speed variation.