Control system for high and low voltage ride through of Ingeteam converter

Abstract

A control system for high and low voltage ride through of an Ingeteam converter belongs to the technical field of wind power grid control, and comprises a main control board assembly, an I / O board, a driving adapter board, a Crowbar assembly, a chopping assembly, an encoder conversion board, a communication module and a UPS power supply assembly, the I / O board, the driving adapter board, the Crowbar assembly, the chopping assembly, the encoder conversion board and the UPS power supply assembly are all connected with the main control board assembly, and the communication module is connected with the main control board assembly. The I / O board is connected with the upper computer through the communication module, and the UPS power supply assembly is connected with the I / O board. According to the invention, the thyristor design of the original Crowbar is changed, and the control effect of the Crowbar module is improved by using the IGBT module; the chopping assembly is added, so that the converter can be effectively protected when the bus voltage fluctuates; the UPS power supply assembly is additionally arranged, and it is guaranteed that the control system has stable power supply when the unit has a short-time mains supply fault; the structural design is completely compatible with original modules, and mounting and dismounting are simple; the converter communication module is added, so that connection with a converter system can be directly established remotely.

Description

Technical Field

[0001] The invention belongs to the technical field of wind power grid control, and in particular relates to a control system for high and low voltage ride-through of an Ingeteam converter. Background Art

[0002] The so-called high and low voltage ride-through refers to the ability of wind turbines to ensure continuous operation without disconnection from the grid within a certain voltage increase or decrease range and time interval when the voltage rises or falls due to a grid fault or disturbance. For a doubly-fed wind turbine generator, its stator is directly connected to the grid, while the rotor is connected to the grid through a converter. When a sudden voltage fault occurs in the grid, its transient process will cause voltage and current impacts on the stator and rotor of the doubly-fed generator, and the converter will be directly affected.

[0003] At present, the specific standard for high and low voltage ride-through in the industry is the "Test Procedure for Fault Voltage Ride-through Capability of Wind Turbines" compiled by the China Electric Power Research Institute of State Grid Corporation of China, which stipulates the test content and test requirements for the high and low voltage ride-through capability of wind turbines.

[0004] Since the original control system does not have the grid high and low voltage fault ride-through control function required by the high and low voltage ride-through standards proposed by the State Grid, in order to be compatible with the original hardware equipment, it is urgent to invent a new control system and apply it to the unit. Summary of the invention

[0005] In order to solve the above-mentioned problems, the present invention proposes: a control system for high and low voltage ride-through of an Ingeteam converter, comprising a main control board assembly, an I / O board, a drive adapter board, a Crowbar assembly, a chopper assembly, an encoder conversion board, a communication module and a UPS power supply assembly, wherein the I / O board, the drive adapter board, the Crowbar assembly, the chopper assembly, the encoder conversion board and the UPS power supply assembly are all connected to the main control board assembly, the I / O board is connected to a host computer via a communication module, and the UPS power supply assembly is connected to the I / O board.

[0006] Furthermore, during the wind turbine fault ride-through period and when the generator fails, the Crowbar component cooperates with the large-capacity power resistor through special control logic. The Crowbar unit discharges the excess energy of the double-fed generator during the wind turbine fault ride-through period to protect the generator winding and the converter power unit from the impact of large current.

[0007] Furthermore, during the fault ride-through of the wind turbine set and when the DC bus of the converter fails, the DC bus of the converter will experience brief and intense fluctuations due to the fluctuation of the grid voltage. The chopper unit stabilizes the DC bus voltage of the converter within a reasonable range through special control logic and large-capacity power resistors, thereby protecting the grid-side equipment, generator windings and converter power units from large current shocks caused by the DC bus voltage fluctuations.

[0008] Furthermore, the chopper component forms a chopper circuit: AK9234 is the converter main module, BUS+ is the DC bus positive pole, BUS- is the DC bus negative pole, the chopper unit is directly connected to the positive and negative poles of the converter DC bus, and the converter control system monitors the DC bus voltage in real time at a high frequency.

[0009] Furthermore, when the wind turbine converter is operating under normal circumstances, the chopper unit does not work and its connection with the DC bus is disconnected inside the chopper module. Once the converter DC bus voltage becomes abnormal, the converter will immediately control the chopper unit to operate. At this time, the chopper unit is connected to the converter DC bus and the DC bus energy is discharged through a high-power resistor.

[0010] Furthermore, the UPS power supply component forms a UPS power supply circuit. When the power grid fails, the UPS system continues to provide stable power to the converter control system for a period of time. A UPS bypass circuit is added to the UPS power supply circuit, and the UPS bypass processing allows the converter control system to obtain power directly from the power grid.

[0011] The beneficial effects of the present invention are:

[0012] 1. The present invention retains the original Ingeteam converter body module and only transforms the control system, which greatly reduces the transformation cost;

[0013] 2. All hardware of the control system of the present invention adopts domestic design, with short spare parts supply cycle and low cost;

[0014] 3. The present invention changes the original Crowbar thyristor design and uses the IGBT module to improve the control effect of the Crowbar module;

[0015] 4. The present invention adds a chopper component, which can effectively protect the converter when the bus voltage fluctuates;

[0016] 5. The present invention adds a UPS power supply component to ensure that the control system has a stable power supply when the unit fails to operate for a short period of time;

[0017] 6. The structural design of the present invention is fully compatible with the original module and is easy to install and disassemble;

[0018] 7. The present invention adds a converter communication module, which can directly establish a connection with the converter system remotely;

[0019] 8. The present invention can enable the wind turbine to meet the high and low voltage ride-through technical requirements proposed by the State Grid. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 The electrical topology diagram of the present invention;

[0021] Figure 2 It is the UPS power supply circuit of the present invention;

[0022] Figure 3 A chopper circuit is added to the present invention;

[0023] Figure 4 The corresponding principle of the input and output points of the I / O board of the present invention Figure 1 ;

[0024] Figure 5 The corresponding principle of the input and output points of the I / O board of the present invention Figure 2 ;

[0025] Figure 6 The corresponding principles of the detection and control ports of the main control board of the present invention Figure 1 ;

[0026] Figure 7 The corresponding principles of the detection and control ports of the main control board of the present invention Figure 2 ;

[0027] Figure 8 The corresponding principles of the detection and control ports of the main control board of the present invention Figure 3 ;

[0028] Fig. 9 The corresponding principles of the detection and control ports of the main control board of the present invention Figure 4 ;

[0029] Fig.10 The corresponding principles of the detection and control ports of the main control board of the present invention Figure 5 . DETAILED DESCRIPTION

[0030] In order to make the technical means and objectives of the present invention easy to understand, the present invention is further described below in combination with specific embodiments. A control system for high and low voltage ride-through of an Ingeteam converter, the electrical schematic diagram (main topology diagram) is as follows: Figure 1As shown, it includes a main control board component, an I / O board, a drive adapter board, a Crowbar component, a chopper component, an encoder conversion board, a communication module and a UPS power supply component. The I / O board, the drive adapter board, the Crowbar component, the chopper component, the encoder conversion board and the UPS power supply component are all connected to the main control board component, the I / O board is connected to the host computer through the communication module, and the UPS power supply component is connected to the I / O board.

[0031] This invention does not change the original main topology of the wind turbine set, and still adopts the original main topology of the standard doubly-fed wind turbine generator set, that is, the stator side of the doubly-fed wind turbine generator is connected to the grid through a high-voltage switchgear, and the rotor side is connected to the grid through a grid-connected contactor. The converter DC bus adopts a pre-charged soft start method at the beginning of the startup stage, and the pre-charging circuit is implemented by a three-phase rectifier and a pre-charging resistor.

[0032] The main control board of the main control board assembly is specially designed for the structure inside the Ingeteam converter cabinet. It is compatible with all the hardware detection and control interfaces of the original converter while meeting the hardware structure installation conditions. At the same time, a heat dissipation component of the control board is added, which is beneficial to the rapid heat dissipation of the control board assembly in the high temperature operating environment of the wind power site and improves the operating stability.

[0033] The I / O board and drive adapter board components are also designed for the structure inside the Ingeteam converter cabinet. The original signal board can be seamlessly replaced. At the same time, the I / O board has dual CAN communication channels and can support multiple field bus communication protocols such as CAN2.0, CANOPEN, profibus, RS232, RS484, etc. Its scalability is good. The drive adapter board supports direct connection of the original control cable, which greatly shortens the time of technical transformation.

[0034] The function of the newly added Crowbar component is mainly reflected in the period of wind turbine fault ride-through and generator failure. The Crowbar component can effectively protect the safety of the generator and converter. Through special control logic and large-capacity power resistors, the Crowbar unit can discharge the excess energy of the double-fed generator during the wind turbine fault ride-through, protecting the generator winding and converter power unit from the impact of large current.

[0035] The function of the newly added chopper component is mainly reflected in the period of wind turbine fault ride-through and when the converter DC bus fails. The chopper component can effectively protect the converter, grid-side equipment and generator safety. During the wind turbine fault ride-through, the converter DC bus will experience short-term strong fluctuations due to the fluctuation of the grid voltage. The function of the chopper unit is to stabilize the converter DC bus voltage within a reasonable range through special control logic and large-capacity power resistors, thereby protecting the grid-side equipment, generator windings and converter power units from large current shocks caused by DC bus voltage fluctuations.

[0036] UPS power supply circuit:

[0037] This part of the electrical circuit is mainly for the transformation of the wind turbine converter control power supply. The original Ingeteam converter control power supply is directly obtained from the power grid. The disadvantage of this circuit is that when the power grid fails, the converter control system power supply will be lost immediately. If the wind turbine is in operation at this time, the sudden loss of control power will cause the converter system to stop modulation, which may cause a fault shutdown at the least, and in severe cases, it will cause direct damage to important equipment such as the wind turbine converter, generator, transformer, and even the risk of causing a wind turbine fire.

[0038] After adding a UPS uninterruptible power supply circuit, this problem can be completely solved. Figure 2 As shown, F3 is the UPS input power protection circuit breaker, F12 is the UPS input fuse, F61 is the UPS output protection circuit breaker, F62 is the UPS bypass protection circuit breaker, K53 is the UPS bypass contactor, G1, G2, G3, G4 are the loads of the UPS, and all are the switching power supplies of the converter control system. The design feature of this circuit is that when the power grid fails, the UPS system can continue to provide a stable power supply for the converter control system for a period of time, ensuring that the wind turbine unit shuts down normally due to a fault, avoiding serious safety risks. At the same time, the UPS system has a complete protection function, and its intelligent detection module can feed back the operating status of the UPS to the converter control system. When the UPS is abnormal, the converter system can accurately judge and protect the shutdown. In response to UPS abnormalities, this design also innovatively adds a UPS bypass system. Maintenance personnel can easily bypass the UPS in some special cases, allowing the converter control system power supply to be directly obtained from the power grid.

[0039] Added chopping circuit:

[0040] like Figure 3As shown, AK9234 is the main module of the converter, BUS+ is the positive pole of the DC bus, BUS- is the negative pole of the DC bus, and the chopper unit is directly connected to the positive and negative poles of the converter DC bus. At the same time, the converter control system monitors the DC bus voltage in real time at a high frequency. When the wind turbine converter is operating under normal conditions, the chopper unit is not working, and its connection with the DC bus is disconnected inside the chopper module. Once the converter DC bus voltage is abnormal, the converter will immediately control the chopper unit to operate. At this time, the chopper unit is connected to the converter DC bus, and the DC bus energy is discharged through a high-power resistor.

[0041] I / O board input and output points corresponding to the schematic diagram:

[0042] The addition of this part of the circuit mainly plays the role of protection and control during the operation of the wind turbine converter. Some feedback circuits are retained from the original Ingeteam converter, and the rest are newly added protection and control circuits. Figure 4 As shown, A1-J3 is a digital input interface. The 1st / 2nd point mainly monitors the closing status of each circuit breaker and air switch. If the circuit is broken, the corresponding fault will be reported to remind the maintenance personnel to check; the 3rd / 4th point mainly monitors whether the stator high-voltage switch cabinet has overcurrent; the 5th / 6th point monitors whether the stator high-voltage switch cabinet overcurrent relay is triggered; the 7th / 8th point is an additional emergency stop switch, which can be pressed in an emergency to quickly shut down the wind turbine; the 9th / 10th and 11th / 12th points are safety chain protection detection of the converter system. A1-J10 is the power supply of the IO board, with a voltage level of 24V-DC.

[0043] like Figure 5 As shown in the figure, the two groups of interfaces A1-J8 and A1-J9 jointly realize the temperature detection function of important components in the converter system, mainly monitoring the temperature of the three-phase winding of the transformer that is prone to high temperature. A1-J6 and A1-J7 are two field bus communication interfaces, which realize the external data exchange of the converter system.

[0044] Schematic diagram of each detection and control port of the main control board:

[0045] like Figure 6As shown in the figure, the design of the control circuit of the main control board includes the main detection and control of all converter systems, among which J9 is the input interface of the generator encoder signal, which can detect the generator speed and angle in real time for the control and protection of the wind turbine; J7 is an external bus communication interface to ensure the data interaction between the converter and the outside world; J25 is the Crowbar resistance voltage detection interface, which is mainly used to determine whether the Crowbar has been opened; J37 is a control cabinet temperature detection point specially added for this model, which supports the signal access of the PT100 sensor; J19 is the internal power supply, which provides stable power supply for the generator encoder.

[0046] like Figure 7 As shown, J26 is the generator stator current detection interface, which is used to control and protect the wind turbine; J5 is the board-level power supply with a voltage level of 24V-DC; J23 and J24 are the grid voltage and stator voltage detection interfaces, which are mainly used to detect the grid voltage and stator voltage, and play a very important role in the control and protection of the converter; J6 is the converter DC bus voltage detection interface, and this feedback signal directly participates in controlling the voltage control of the DC bus and whether the chopper module and the Crowbar unit are in action; the optical fiber interface is a new medium for controlling the Crowbar opening and receiving the Crowbar opening signal.

[0047] While the main control board detects various analog signals, it also needs to monitor digital signals and control intermediate relays at all times. Figure 8 As shown, the following electrical circuit is used to realize this function. The J10 interface is compatible with the functions of digital input and output. The 1st / 2nd and 11th / 12th points are the closing feedback signals of the grid-connected contactor and the stator high-voltage switchgear on the grid side; the 3rd / 4th points are the closing signal instructions of the grid-side contactor; the 5th / 6th points are the closing signal instructions of the pre-charging contactor; the 7th / 8th points are the output signals of whether the converter status is normal, and this signal is transmitted to the main control PLC system of the wind turbine; the 9th / 10th points are the closing command signals of the stator high-voltage switchgear.

[0048] like Fig. 9 As shown, the J17 and J18 interfaces are for current detection of the grid-side converter and the machine-side converter, and the detection results are directly involved in the control and protection of the converter; J8 is the driving power supply of the converter IGBT power module. Through the power filtering and voltage stabilization of the main control board, it can ensure that a stable driving power supply is provided to the converter IGBT.

[0049] The specific implementation steps of the transformation application of the present invention are as follows:

[0050] 1) Remove the original control board assembly and directly replace the main control board assembly, I / O board, drive adapter board assembly, and encoder adapter board assembly;

[0051] 2) Add UPS power system;

[0052] 3) Add a chopper circuit to the DC bus;

[0053] 4) Replace the Crowbar assembly;

[0054] 5) Reconnect the original I / O port to the new I / O board assembly;

[0055] 6) Connect the original current detection circuit, voltage detection circuit, grid control circuit, and each contactor feedback signal circuit to the newly added main control board;

[0056] 7) Add a converter communication module and connect its communication line and power cable.

[0057] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical solutions and concepts of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A control system for high and low voltage ride-through of an Ingeteam converter, characterized in that: It includes a main control board component, an I / O board, a drive adapter board, a Crowbar component, a chopper component, an encoder conversion board, a communication module and a UPS power supply component. The I / O board, the drive adapter board, the Crowbar component, the chopper component, the encoder conversion board and the UPS power supply component are all connected to the main control board component. The I / O board is connected to the host computer through the communication module, and the UPS power supply component is connected to the I / O board.

2. The control system of Ingeteam converter high and low voltage ride through according to claim 1, characterized in that: During the wind turbine fault ride-through period and when the generator fails, the Crowbar component cooperates with the large-capacity power resistor through special control logic. The Crowbar unit discharges the excess energy of the double-fed generator during the wind turbine fault ride-through period to protect the generator winding and the converter power unit from the impact of large current.

3. The control system of Ingeteam converter high and low voltage ride through according to claim 1, characterized in that: During the fault ride-through period of the wind turbine set and when the DC bus of the converter fails, the DC bus of the converter will experience short-term strong fluctuations due to the fluctuation of the grid voltage. The chopper unit stabilizes the DC bus voltage of the converter within a reasonable range through special control logic and large-capacity power resistors, thereby protecting the grid-side equipment, generator windings and converter power units from large current shocks caused by the DC bus voltage fluctuations.

4. The control system for high and low voltage ride through of the Ingeteam converter according to claim 3, characterized in that: The chopper component forms a chopper circuit: AK9234 is the main module of the converter, BUS+ is the positive pole of the DC bus, BUS- is the negative pole of the DC bus, the chopper unit is directly connected to the positive and negative poles of the converter DC bus, and the converter control system monitors the DC bus voltage in real time at a high frequency.

5. The control system for high and low voltage ride through of the Ingeteam converter according to claim 4, characterized in that: When the wind turbine converter is operating under normal circumstances, the chopper unit does not work and its connection with the DC bus is disconnected inside the chopper module. Once the converter DC bus voltage becomes abnormal, the converter will immediately control the chopper unit to operate. At this time, the chopper unit is connected to the converter DC bus and the DC bus energy is discharged through a high-power resistor.

6. The control system of Ingeteam converter high and low voltage ride through according to claim 1, characterized in that: The UPS power supply components form a UPS power supply circuit. When the power grid fails, the UPS system continues to provide stable power to the converter control system for a period of time. A UPS bypass circuit is added to the UPS power supply circuit, and the UPS bypass processing allows the converter control system to obtain power directly from the power grid.

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