Device and method for testing a power module

Abstract

The present invention relates to a device and a method for testing a power module. Specifically, this device for testing a power module (Mp) in a group of power modules (Mp) connected together includes: reactive power compensation devices (1, 2) capable of compensating for reactive power transmitted between the power module under test and other power modules; and a device (UT2) for monitoring the power generated by the power module under test, which includes a device (M comp ) for comparing the generated power with at least one threshold.

Description

Technical Field

[0001] The present invention relates to a device and method for testing a set of electric power modules, and more particularly, to a network of multiphase and multi-channel synchronous electric machines and their associated multi-channel power converters. Background Art

[0002] For example, in a non-limiting application, it is intended to integrate power modules into a wind turbine nacelle.

[0003] Wind turbines incorporating power modules are connected to each other and to an electric power grid that consumes power in order to establish an offshore power plant.

[0004] Before putting the power modules into production, it is necessary to check the electrical and mechanical characteristics of each module and the connections between the modules and connect them to the power grid.

[0005] The test procedure seeks to verify the operation of each power module, i.e., the operation of the control and acquisition chain (which includes: sensors, interface modules, actuators, power chains, and also the connections between the power modules, as well as the connections between the power modules and the power grid to which they are connected via the network of power modules).

[0006] Figure 1 An offshore wind farm (M) is shown where a state-of-the-art test procedure can be performed.

[0007] The wind turbines H are generally connected to an offshore substation S in groups G1,..., Gn of six wind turbines via submarine cables C1,..., Cn of large cross-section and long distance (e.g., 50 km).

[0008] Each turbine H includes a power module and a turbine controller, and the power module includes a multiphase and multi-channel synchronous electric machine and its associated multi-channel power converter.

[0009] For example, the wind turbine H provides a rated electrical power output of 6 MW.

[0010] The substation S includes a platform PT, and the platform PT is anchored to the seabed and is located above sea level.

[0011] The substation S also includes a generator set G, an inductor bar L, and a wind turbine field controller MC. The generator set G has at least one diesel internal combustion engine and generally delivers 1 MW of electrical power.

[0012] The generator set G generates the electrical power required to operate the wind turbines H, especially during the test phase.

[0013] The inductor bar L is connected to the cables C1,..., C2 in order to compensate for the reactive power generated by the wind farm and transmitted by the cables C1 and C2 and to stabilize the circuit.

[0014] Test procedures for wind farms are known from the prior art. During the test procedure, inductor bars Lt and resistor banks R are connected to cables C1 and C2 to compensate for reactive power and consume active power, respectively.

[0015] Now, a test procedure for a wind turbine Ha will be considered.

[0016] The various phases of the test procedure are controlled by a wind turbine farm controller MC and a wind turbine controller incorporated in the wind turbine Ha.

[0017] In a first phase, the wind turbine Ha is driven to rotate by the power delivered by a generator set G.

[0018] Then, the blades of the turbine Ha are oriented such that they are driven by the wind and the turbine Ha delivers electrical power.

[0019] The power generated by the wind turbine Ha and consumed in the resistor bank R is compared with a reference value.

[0020] However, the usual test procedures have several drawbacks.

[0021] Before connecting the regulating station to the network, the test device first needs to use inductor bars and resistor banks, which will be removed at the end of the test procedure.

[0022] These components are only used during the test procedure and require storage space on a platform that will only be used during the test procedure, which generally lasts for 6 months, while the lifespan of the wind turbine farm is generally 25 years.

[0023] In addition, the test procedure is limited to a reduced operating power range, generally up to 20% of the rated power of the module.

[0024] Therefore, the usual test procedure does not allow the power module to be tested at its rated power. Summary of the Invention

[0025] In view of the above, it is proposed to overcome the deficiencies of the power module procedures according to the prior art.

[0026] Therefore, according to one aspect, a device for testing modules in a group of power modules connected together is proposed.

[0027] According to an implementation mode, the device includes: a reactive power compensation device capable of compensating for reactive power transmitted between the power module under test and other power modules; and a power control device for the power generated by the power module under test, which includes a device for comparing the generated power with at least one threshold.

[0028] Advantageously, the reactive power compensation device consists of a power module configured to compensate for the reactive power exchanged with the power module under test.

[0029] Preferably, each power module includes a polyphase and multi-channel synchronous electric machine having a stator including several groups of three phases, with a magnetic coupling level allowing each channel to be controlled individually.

[0030] Advantageously, each channel of the polyphase and multi-channel synchronous electric machine operates in motor mode or generator mode.

[0031] The device may also include power generation means connected to the power module and capable of accelerating the module under test.

[0032] Advantageously, the power generation means includes a generator set including a diesel engine.

[0033] According to another implementation, the power generation means includes an additional power module.

[0034] Depending on one aspect, the power module as defined above is embedded in a wind turbine nacelle.

[0035] According to yet another aspect, a test procedure for a group of power modules connected together is proposed.

[0036] According to an implementation mode, the reactive power transmitted between the power module under test and other power modules is compensated, the power generated by the power module under test is controlled, and the generated power is compared with at least one threshold.

[0037] Preferably, the process includes:

[0038] A start-up phase during which the power module under test is supplied until it reaches a subsequent connection speed;

[0039] And a phase for controlling the power generated by the power module under test, the power module under test having a polyphase and multi-channel synchronous electric machine having a stator including phases connected together in groups of three phases, and wherein the rotor of the electric machine is driven at a predetermined rotational speed via at least one group of three phases, one or more other groups of three phases of the power module under test operate in generator mode, and an electromagnetic torque is applied to the rotor of the polyphase and multi-channel synchronous electric machine of the power module under test. Description of the Drawings

[0040] Other objects, features, and advantages of the present invention will become apparent upon reading the following description with reference to the accompanying drawings, which are given by way of non-limiting example only, in which:

[0041] - Mentioned above Figure 1 An offshore wind farm in which a test program at the state of the art can be executed;

[0042] - Figure 2 An offshore wind farm in which a test program according to the present invention is executed;

[0043] - Figure 3 An electrical power diagram showing an electrical power module including a polyphase synchronous electrical machine and a multi-channel power converter;

[0044] - Figure 4 Showing the channels of a multi-channel power converter; and

[0045] - Figure 5 Describing a wind turbine field test program;

[0046] - Figure 6 Showing the electrical power exchange of a test process according to the present invention; and

[0047] - Figure 7 Describing a test program for a wind turbine nacelle power module. Detailed description

[0048] Reference is made to Figure 2 , which shows a test device for a group of power modules Mp connected together, each power module including a polyphase and multi-channel synchronous electrical machine and an associated multi-channel power converter.

[0049] Here, the power module Mp is a generator module and a power consumption device.

[0050] For example, in a non-limiting application, each power module Mp is integrated into the nacelle of a wind turbine.

[0051] The wind turbines form a field CH of offshore wind turbines (M).

[0052] For the sake of clarity of expression, the wind turbine field as shown includes a group of six variable blade wind turbines H1, H2, H3, H4, H5 and H6, each including: connection terminals E1, E2, E3, E4, E5 and E6 for connection to a cable C3; a power module Mp; and a device for controlling the power generated by the power module, which includes a power processing and control unit UT2. The cable C3 connects the wind turbines H1, H2, H3, H4, H5 and H6 to each other and to a substation S1 with a platform PT1, the platform PT1 being anchored to the seabed and located above sea level (M).

[0053] Of course, the wind turbine field CH can include several groups, each group including several wind turbines, for example 6 wind turbines.

[0054] Wind turbines in the same batch are connected to the regulating station and to each other via the same cable.

[0055] The substation S1 includes: an inductor L1, a wind turbine field processing and monitoring unit UT1, and a generating set Ge mounted on a platform PT.

[0056] The generating set Ge generates electrical power, which is supplied to the substation S1 and the wind turbines H1, H2, H3, H4, H5, and H6 via a cable C3. For example, it includes at least one diesel internal combustion engine with an electrical output of 1 MW.

[0057] The inductor L1 stabilizes the circuit including the wind turbines, the cable C3, and the substation S1.

[0058] The wind turbines H1, H2, H3, H4, H5, and H6 are identical in structure.

[0059] The processing and monitoring unit UT1 controls the wind turbine field CH by regulating the power exchange in the wind turbine field (especially between the wind turbines and the substation S1), and the processing and power control unit UT2 controls the wind turbines (where the processing and power control unit is implemented).

[0060] In other words, the power processing and control unit UT2 controls the power unit Mp and the orientation of the wind turbine blades.

[0061] The two processing units UT1 and UT2 interact with each other.

[0062] For example, the processing units UT1 and UT2 are based on microprocessors.

[0063] It can be any device capable of monitoring a group of power modules.

[0064] For example, in the example described, it is a device capable of controlling the power modules of the wind turbines and orienting the blades of the wind turbines. These may include microcontrollers.

[0065] The device further includes: a reactive power compensation device capable of compensating the reactive power transmitted between the tested power module and other power modules; and a device M for comparing the power generated by the tested power module with at least one threshold comp .

[0066] Preferably, the comparison device M comp is incorporated into the processing unit UT2 of the wind turbine being tested.

[0067] Of course, it can be any device capable of comparing the power generated by the tested power module with at least one threshold and incorporated into the control device.

[0068] It can be a device made of a microprocessor.

[0069] Reference Figure 3 , which shows the electrical power diagram of the nacelle of the wind turbine H1.

[0070] As we can see, the wind turbine nacelle includes: a three-phase transformer 3 connected to a connector E1, and an electrical power module including a polyphase and multi-channel electric machine 2 and a three-phase multi-channel power converter 1.

[0071] The in-phase inputs of the power converter 1 are connected to each other and to the corresponding outputs of the three-phase transformer 3.

[0072] The entire device including the power converter 1 and the polyphase and multi-channel electric machine 2 is controlled by a processing unit UT2.

[0073] The synchronous polyphase and multi-channel electric machine 2 includes a stator and a rotor. The stator includes a plurality of phases that are a multiple of 3. The phases are connected to each other by groups of three phases. By way of the following non-limiting example, three phases of one group are connected in a star configuration. Of course, when the phases are connected in any configuration (particularly but not exclusively in a delta configuration), it does not depart from the present invention. The star has strong magnetic decoupling between them. Thus, the magnetic flux generated by one star configuration does not interfere with another star configuration. The magnetic decoupling level allows each channel to be controlled individually.

[0074] In Figure 3 , the machine 2 has, for example, nine phases, which are grouped into three sets of star-connected three phases 4, 5, and 6.

[0075] The power converter 1 has a plurality of identically formed channels. Each output of the channels is connected to a set of three phases of the electric machine 2 in a star configuration. Thus, the number of channels of the power converter 1 is equal to the number of sets of three phases of the machine 2 in a star configuration. The inputs of the in-phase channels are connected to each other and to the corresponding outputs of the transformer 3.

[0076] In Figure 3 , the electric machine has three sets of star-connected three phases 4, 5, and 6. Thus, the power converter 1 includes three channels 7, 8, and 9.

[0077] Reference Figure 4 , which shows the configuration of channel 7 of the multi-channel power converter 1 operating in motor or generator mode. All channels are identically formed.

[0078] Channel 7 includes a harmonic filtering device 10 intended to connect its input to the other inputs of the power converter channel 1 and the transformer 3.

[0079] The output of the filtering device 10 is connected to the input of the reversibly controlled bridge rectifier 11.

[0080] The output of the bridge rectifier 11 is connected to the capacitor bank 12.

[0081] The capacitor bank 12 includes two sets of capacitors connected in series, whose ends are connected to the bridge rectifier 11, connected to the braking chopper 13, and connected to the input of the reversible voltage inverter 15, and whose midpoint between the two capacitors is connected to the braking chopper. The second capacitor bank 14 is the same as the capacitor bank 12, and the second capacitor bank 14 is connected to the input of the reversible voltage inverter 15.

[0082] The midpoint between the two capacitor groups of the capacitor bank 14 is connected to the reversible voltage inverter 15. The output of the voltage inverter 15 is connected to the dV / dT filter 16. The output of the filter 16 is connected to the star-configured grouped three-phase of the electric machine 2.

[0083] The filtering device 10, the controlled and reversible bridge rectifier 11, the braking chopper 13, the reversible voltage inverter 15, and the dV / dT filter 16 are not discussed in detail here because these elements are known to those skilled in the art.

[0084] Now, in Figure 5 described Figure 2 the first implementation mode of the wind turbine field test procedure shown in

[0085] In this implementation mode of the wind turbine field test procedure, one of the turbines operates in the reactive power compensation mode, and the operation of the other turbine is tested by controlling the power generated by the turbine.

[0086] In other words, the reactive power transmitted between the power module under test and other power modules is compensated, the power generated by the power module under test is controlled, and the generated power is compared with at least one threshold.

[0087] In step 1, the first power module Mp is incorporated into one of the wind turbines (in this case the reference wind turbine H1), and includes a multi-phase and multi-channel electric machine 2 and a multi-channel power converter 1. The first power module Mp operates to compensate for the reactive power generated by the wind farm CH and transmitted by the cable C3. This operating mode of the wind turbine is called the reactive power compensation mode CPR.

[0088] The setpoint of the reactive power to be compensated is determined by the processing unit UT1 and transmitted to the processing unit UT2 of the wind turbine H1, which controls the H1 power module to compensate for the reactive power.

[0089] Then in step 2, the power module incorporated into the other turbine H2 is tested by controlling the power generated by the turbine.

[0090] Of course, for each module incorporated into one of the wind turbines H1, H2, H3, H4, H5, and H6, the power module test procedure is the same.

[0091] In other words, the reactive power compensation device consists of a power module Mp incorporated into the reference wind turbine H1, which is configured to compensate for the reactive power exchanged with the tested H2 power module.

[0092] The wind turbine operating in the reactive power compensation mode is any one of the wind turbines H1, H2, H3, H4, H5, and H6 other than the tested wind turbine.

[0093] In the case of a wind farm with several batches, at least one wind turbine in each batch should operate in the reactive power compensation mode CPR during the test procedure.

[0094] This procedure is repeated for each wind turbine in the wind farm.

[0095] This procedure can be carried out for one wind turbine at a time, for several wind turbines at a time, or for all the wind turbines in the field in one test operation.

[0096] The power used will be adjusted according to the number of wind turbines tested simultaneously.

[0097] In the CPR mode, the coils of phase groups 4, 5, and 6 of the electric machine 2 are used as inductors.

[0098] The reversible voltage inverter 15 regulates the phase shift between the current flowing through each phase and the voltage at the terminals of each phase in order to compensate for the reactive power in the grid.

[0099] The voltage inverter is controlled by the wind turbine farm processing unit UT1 in order to deliver the reactive power compensation setpoint.

[0100] Advantageously, no additional inductor bars are required to carry out the wind turbine farm test procedure.

[0101] Figure 6 Shows the electric power exchange flow of the star component incorporated into the wind turbine H2 and the associated voltage inverter.

[0102] As shown in this figure, the power P Ge is transmitted by the transformer 3 and supplied to the power converter 1.

[0103] Phase groups 4 and 5 of the machine 2 are supplied by the motor powers P mot1 and P mot2 and the motor powers P mot1 and P mot2Supplied by the power converter 1, and the phase group 6 generates the power P that supplies the converter 1 gen .

[0104] Repeat the test procedure for each three-phase group or for multiple three-phase groups in star configuration of the electric machine 2 and the relevant channels of the tested power converter 1.

[0105] Figure 7 Describe in detail the procedure for testing the power module of the wind turbine nacelle (previously described in Figure 5 step 2) and in particular the procedure for group 21 visible in Figure 6 . Group 21 includes the three-phase subgroup 6 in star configuration and the channel 9 of the power converter 1.

[0106] The rotor of the electric machine 2 is rotated by the component 20, which includes the three-phase 4 and 5 in star configuration, which are supplied by the channels 7 and 8 of the power converter 1.

[0107] During step 2.1 of the start of the test procedure, the component 20 is powered by a power generation device capable of accelerating the power module under test until it reaches the connection speed.

[0108] The connection speed corresponds to the rotational speed at which the electric machine and the power converter would generate sufficient power to supply the grid (if they operate in generator mode). For example, in the case of a wind turbine, the connection speed is 3.7 rpm.

[0109] The power generation device includes the generator set Ge of the substation S1, which is connected to the terminal E1 via the transformer 3.

[0110] The electric power P supplied by the generator set Ge Ge is transmitted via the cable C3 to the wind turbine H2.

[0111] The electric power transmission is controlled by the wind turbine field processing unit UT1 in power regulation mode and by the wind turbine processing unit UT2 of the wind turbine H2.

[0112] The three-phase groups 4 and 5 in star configuration are called the motor groups.

[0113] The number of three-phase motor groups in star configuration is selected such that the total rated drive power delivered by the star is at least equal to the rated power of the group under test.

[0114] The speed of the electric machine 2 is controlled by the processing unit UT2 of the tested wind turbine H2.

[0115] In step 2.2, when the rotor of the electric machine 2 reaches the connection speed and after synchronization of the component 21, the tested component 21 is controlled so that it operates in generator mode.

[0116] Group 21 controls the torque of the electric machine 2.

[0117] The electric power P generated by the assembly 21 gen is transmitted to the electric motor assembly 20.

[0118] The processing unit UT2 of the wind turbine controls group 21 and orients the blades of the wind turbine H2 such that the motor powers P mot1 and P mot2 consumed by group 20 sum up to the power P gen .

[0119] In step 2.3, when the sum of the motor powers P mot1 and P mot2 consumed by group 20 equals the power P gen , the power control phase generated by the power module under test starts.

[0120] The generator set Ge no longer supplies electric power to the wind turbine H2.

[0121] The wind turbine H2 is now autonomous and controlled by the processing unit UT2.

[0122] Assembly 21 includes a set of three-phase 6 in star configuration and the channels 9 of the associated power converter 1. The reactive electromagnetic torque applied to the rotor of the electric machine 2 generated by assembly 21 gradually increases. As a result, the rotational speed of the rotor decreases. The processing unit UT2 increases the drive power delivered by unit 20 until the speed setpoint is reached. Thus, the reactive torque can be increased until the power generated by the reactive torque equals the motor power generated by assembly 20.

[0123] The power generated by assembly 21 is compared with the desired value in order to verify the operation of assembly 21 by comparison M comp .

[0124] This test procedure has the advantage that the power module is tested over its entire power range by using the acquisition chain, control chain and power chain of the module, for example in the case of a wind turbine.

[0125] Advantageously, the test device has a configuration that ensures the active power exchange within the power module.

[0126] In other words, during the second test phase, the power module operates autonomously by no longer exchanging active power with the wind turbine field.

[0127] Therefore, performing the test procedure does not require a resistance test bench and the power consumption of the generator set is reduced.

[0128] Advantageously, the platform of the packaging station is smaller compared to the known state of the art.

[0129] According to another method of executing the test program, the device for generating electricity includes, for example, additional power modules operating in generator mode incorporated in a wind turbine.

[0130] These generating devices replace the generator set Ge.

[0131] The wind turbine operates in generator mode and supplies electrical power to the wind turbine under test.

[0132] The test program is the same as that described in the previous implementation mode.

[0133] In this implementation mode, the wind farm controller operates in voltage regulation mode, and the wind turbine generator controller operates in power regulation mode by outputting power to the grid.

[0134] In other words, the power required during the start-up phase of the test program is generated by the wind. Therefore, the fuel consumption of the generator set is zero.

Claims

1. A device for testing a power module (Mp) in a set of power modules (Mp) connected together, characterized in that, The device comprises: reactive power compensation devices (1, 2) capable of compensating the reactive power transmitted between the power module under test and other power modules, each power module other than the power module under test being capable of operating in a reactive power compensation mode; and a device (UT2) for controlling the power generated by the power module under test, the device including a device (M comp ) for comparing the generated power with at least one threshold value Wherein, the reactive power compensation device is constituted by a power module in the power module configured to compensate for the reactive power exchanged with the tested power module.

2. The device according to claim 1, wherein Each power module includes a multi-phase and multi-channel synchronous electric machine (2), and the multi-phase and multi-channel synchronous electric machine has a stator including multiple sets of three-phase (4, 5, 6), which has a magnetic coupling level allowing each channel to be controlled individually.

3. The device according to claim 2, characterized in that, Each channel of the multi-phase and multi-channel synchronous electric machine (2) operates in a motor mode or a generator mode.

4. The device according to any one of claims 1 to 3, characterized in that The device further includes a power generation device connected to the power module and capable of accelerating the tested power module.

5. The device according to claim 4, characterized in that, The power generation device includes a generator set (Ge), and the generator set includes a diesel engine.

6. The device according to claim 4, characterized in that, The power generation device includes an additional power module (Mp).

7. The device according to any one of claims 1 to 3, characterized in that, The power module is a power module (Mp) embedded in a wind turbine nacelle.

8. A method for testing a power module (Mp) in a group-connected power module, characterized in that, The reactive power transmitted between the tested power module and other power modules is compensated by the reactive power compensation device, wherein, except for the tested power module, each power module can operate in a reactive power compensation mode, monitor the power generated by the tested power module, and compare the generated power with at least one threshold. Wherein, the reactive power compensation device is constituted by a power module in the power module configured to compensate for the reactive power exchanged with the tested power module.

9. The method according to claim 8, wherein The method includes: A startup phase, during which the tested power module is supplied until it reaches a following connection speed; and A phase for controlling the power generated by the tested power module, the tested power module including a multi-phase and multi-channel synchronous electric machine (2), the multi-phase and multi-channel synchronous electric machine including a stator, the stator including phases connected together by sets of three-phase (4, 5, 6), and wherein the rotor of the electric machine is driven at a predetermined rotational speed via at least one set of three-phase, one or more other sets of three-phase of the tested power module operate in a generator mode, and an electromagnetic torque is applied to the rotor of the multi-phase and multi-channel synchronous electric machine of the tested power module.

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