Control circuit and method for switching from battery pitch failure to ac pitch

Abstract

The application discloses a control circuit and method for switching from battery pitch collection failure of a variable pitch system to AC pitch collection, comprising a main control DO interface circuit, a reset voltage circuit, a reset circuit and a main control rpm-ok signal circuit; the main control DO interface circuit comprises a DO interface and a relay coil connected with the DO interface; the reset voltage circuit is connected with the reset circuit through a normally open node of the relay; and the main control rpm-ok signal circuit is connected with a direct-current variable pitch system through a normally closed node of the relay. In the battery pitch collection failure state, the AC pitch collection can be switched as long as the AC variable pitch power supply voltage is normal, so that malignant accidents such as fan overspeed, machine burning and machine falling are avoided, and the last safety protection is provided for the direct-current variable pitch system.

Description

Technical Field

[0001] This invention relates to the field of wind turbine safety technology, specifically to a control circuit and method for switching to AC propulsion in a pitch system when battery propulsion fails. Background Technology

[0002] In a DC pitch system, if the wind turbine safety chain is broken or the pitch communication fails, it is impossible to switch to AC pitch recovery after battery-powered pitch recovery fails. The reasons for this inability to switch to AC pitch recovery after battery-powered pitch recovery failure are analyzed below:

[0003] like Figure 1 The black circle indicates the fast battery pitch control output signal 103 of the main control and DC pitch system. When 103 is high, the pitch system is in AC pitch mode. At this time, the safety chain relay k11.8 and the main control fast pitch control relay k16.2 are connected. When the main control starts battery pitch control, the fast pitch control relay k16.2 is disconnected, and the output of 103 is low.

[0004] When the safety chain breaks, safety chain relay K11.8 disconnects, and relay 103 remains low. The DC pitch system is in battery-operated pitch recovery mode. When the main controller attempts to switch to AC pitch recovery, the fast pitch recovery relay K16.2 returns from disconnected to connected, but this does not change the persistent low-level state of relay 103. This is because the safety chain is interrupted, causing safety chain relay K11.8 to disconnect. This explains why switching to AC pitch recovery is impossible after battery-operated pitch recovery fails. Summary of the Invention

[0005] To address the aforementioned shortcomings in the prior art, the present invention provides a control circuit and method for switching to AC pitch recovery in a pitch system when battery pitch recovery fails, solving the problem that the system cannot switch to AC pitch recovery after a wind turbine safety chain failure or pitch communication failure.

[0006] To achieve the above-mentioned objectives, the technical solution adopted by the present invention is as follows: a control circuit for switching from battery-driven propeller recovery to AC-driven propeller recovery in a DC pitch system, comprising a main control DO interface circuit, a reset voltage circuit, a reset circuit, and a main control rpm-ok signal circuit.

[0007] The main control DO interface circuit includes a DO interface and a coil of a relay DA connected to the DO interface. The reset voltage circuit is connected to the reset circuit through the normally open node of the relay DA. The main control rpm-ok signal circuit is connected to the DC pitch system through the normally closed node of the relay DA.

[0008] Further, the master DO interface circuit further comprises a master PLC and a freewheeling diode, one end of the coil of the relay DA and one end of the freewheeling diode are connected to the DO interface of the master PLC, and the other end of the coil of the relay DA and the other end of the freewheeling diode are grounded.

[0009] Further, the reset voltage circuit comprises, in sequence, a personal safety chain, a yaw reverse switch, a yaw forward switch, a vibration switch, a main shaft overspeed switch, a gearbox overspeed switch, and a master internal safety switch, the personal safety chain comprises, in sequence, a blade maintenance switch, a frequency converter emergency stop switch, and a cabin emergency stop switch, the blade maintenance switch and the yaw reverse switch are connected through the normally open node of the relay DA to output a reset voltage and connect a reset circuit, the cabin emergency stop switch is connected to a 24V voltage, and the master internal safety switch is connected to the coil of the relay K11.8 and the coil of the relay K11.9 through the normally closed node of the relay K11.8 and the normally closed node of the relay K11.9 respectively.

[0010] Further, the reset circuit comprises a relay K16.2, a relay K16.4, and a relay K16.6, the A2 end of the coil of the relay K16.2, the A2 end of the coil of the relay K16.4, and the A2 end of the coil of the relay K16.6 are connected to an N-UPS signal, the A1 end of the coil of the relay K16.2, the A1 end of the coil of the relay K16.4, and the A1 end of the coil of the relay K16.6 are connected to a 230V-UPS signal through a switch, the normally open node 3 of the relay K16.2 and the normally open node 3 of the relay K16.4 are connected to a +24V OUT signal, the normally open node 4 of the relay K16.2 is connected to a 103 signal interface through the normally open node of the relay K11.8, and the 103 signal interface is connected to the normally open node of the relay DA, and the normally open node 4 of the relay K16.4 is connected to a 105 signal interface through the normally open node of the relay K11.9.

[0011] Further, after the relay DA is turned on, the 103 signal interface outputs a high level to start AC collection.

[0012] Further, the master rpm-ok signal circuit comprises a generator overspeed module, a normally closed node of the relay DA, and a normally closed node of the relay K40.5, the output end 26.9 of the generator overspeed module is connected to a HUB signal through the normally closed node of the relay DA and the normally closed node of the relay K40.5, and the output end 26.8 of the generator overspeed module is also connected to the HUB signal.

[0013] A control method for switching from battery collection to AC collection in a variable pitch system, specifically:

[0014] After the battery pitch-in x seconds, the master PLC judges whether the blade angle change is less than m°, if yes, it is considered that the battery pitch-in fails, and immediately switches to AC pitch-in;

[0015] Or after the battery pitch-in y seconds, the master PLC judges whether the blade angle change is less than n°, if yes, it is considered that the battery pitch-in fails, and immediately switches to AC pitch-in;

[0016] After switching to AC pitch-in, the master DO interface circuit outputs high level, the relay DA acts, and the AC pitch-in is started.

[0017] The beneficial effects of the above further scheme are: providing 2 opportunities for judging the blade angle change, improving the accuracy of the judgment, being able to switch to AC pitch-in in time, and in the case of battery pitch-in failure, as long as the AC pitch-in power supply is normal, it can be switched to AC pitch-in.

[0018] The beneficial effects of the present application are: as long as the AC pitch-in power supply voltage is normal in the case of battery pitch-in failure, it can be switched to AC pitch-in, avoiding fan overspeed, machine burning and other malignant accidents, and providing the last safety protection for the DC pitch-in system. BRIEF DESCRIPTION OF DRAWINGS

[0019] Figure 1 It is a battery pitch-in control diagram in the prior art;

[0020] Figure 2 It is a master DO interface circuit diagram in the present application;

[0021] Figure 3 It is a reset voltage circuit diagram in the present application;

[0022] Figure 4 It is a reset circuit diagram in the present application;

[0023] Figure 5 It is a master rpm-ok signal circuit in the present application. DETAILED DESCRIPTION

[0024] The specific embodiments of the present application are described below, so that those skilled in the art can understand the present application, but it should be clear that the present application is not limited to the scope of the specific embodiments, and for those skilled in the art, it is obvious that various changes are within the spirit and scope of the present application defined and determined by the appended claims, and all the inventions utilizing the concept of the present application are within the scope of protection.

[0025] A control circuit for switching from battery pitch-in failure to AC pitch-in of a DC pitch-in system, comprising a master DO interface circuit, a reset voltage circuit, a reset circuit and a master rpm-ok signal circuit;

[0026] The master DO interface circuit includes a DO interface and a relay coil connected with the DO interface, the reset voltage circuit connects the reset circuit through the normally open node of the relay, and the master rpm-ok signal circuit connects the direct current variable pitch system through the normally closed node of the relay.

[0027] As shown in Figure 2 , the master DO interface circuit further includes a master PLC and a freewheeling diode, the DO interface of the master PLC is connected with one end of the coil of the relay DA and one end of the freewheeling diode respectively, and the other end of the coil of the relay DA and the other end of the freewheeling diode are both grounded. The master PLC is a Bürklin+effector PLC, and the model number is DIO264.

[0028] As shown in Figure 3 , the reset voltage circuit includes a personal safety chain, a yaw reverse switch, a yaw forward switch, a vibration switch, a main shaft overspeed switch, a gearbox overspeed switch and a master internal safety switch connected in sequence, the personal safety chain includes a blade maintenance switch, a frequency converter emergency stop switch and a cabin emergency stop switch connected in sequence, the blade maintenance switch and the yaw reverse switch are connected with the reset circuit through the normally open node of the relay DA, the cabin emergency stop switch is connected with a 24V voltage, and the master internal safety switch is connected with the coil of the relay K11.8 and the coil of the relay K11.9 through the normally closed node of the relay K11.8 and the normally closed node of the relay K11.9 respectively.

[0029] The reset voltage is taken from the rear end of the safety chain blade maintenance switch, as shown in Figure 3 , the black square; it can be ensured that in the state of the fan personal safety chain being disconnected, for example, fan maintenance is carried out in the cabin, when the blade maintenance switch is disconnected or the cabin safety box or the cabin emergency stop button is actuated, the alternating current pitch will not be started, and it can only work under the condition that the equipment safety chain is disconnected.

[0030] As shown in Figure 4As shown, the reset circuit includes relay K16.2, relay K16.4, relay K16.6, the A2 end of the coil of the relay K16.2, the A2 end of the coil of the relay K16.4, and the A2 end of the coil of the relay K16.6 are all connected to the N-UPS signal, the A1 end of the coil of the relay K16.2, the A1 end of the coil of the relay K16.4, and the A1 end of the coil of the relay K16.6 are all connected to the 230V-UPS signal through the switch, the normally open node 3 of the relay K16.2 and the normally open node 3 of the relay K16.4 are both connected to the +24V OUT signal, the normally open node 4 of the relay K16.2 is connected to the 103 signal interface through the normally open node of the relay K11.8, the 103 signal interface is connected to the normally open node of the relay DA, the normally open node 4 of the relay K16.4 is connected to the 105 signal interface through the normally open node of the relay K11.9. The black circle shown is the 103 reset signal wiring diagram. After the relay DA is turned on, the 103 signal interface outputs a high level, and the AC collector is started. The node of the relay K16.6 is in the existing battery collector control system, and the specific position and connection relationship are not the focus of the present application, the N-UPS signal is an uninterruptible power supply signal, and the 230V-UPS signal is a 230V uninterruptible power supply signal.

[0031] As shown in Figure 5 The main control rpm-ok signal circuit includes a generator overspeed module, a normally closed node of the relay DA, and a normally closed node of the relay K40.5, the output end 26.9 of the generator overspeed module is connected to the HUB signal through the normally closed node of the relay DA and the normally closed node of the relay K40.5, the output end 26.8 of the generator overspeed module is also connected to the HUB signal, and the coil of the relay K40.5 is in the existing battery collector control system, and the specific position and connection relationship are not the focus of the present application. The HUB signal is a multi-port repeater interface signal.

[0032] When the battery collector fails and needs to be switched to the AC collector, the main control DO outputs a high level signal, and the relay DA is energized. The normally open node thereof forces the 103 signal to be high level, at this time, the variable pitch system is switched from the battery collector to the AC collector state. The normally closed node thereof disconnects the rpm-ok signal between the main control and the variable pitch, and the AC fast collector is activated to the 92-degree safe position through the variable pitch controller.

[0033] A control method for switching a battery collector of a variable pitch system to an AC collector when the battery collector fails, specifically comprising:

[0034] After starting the battery collector for 3 seconds, the main control judges whether the blade angle change is less than 12°, if yes, it is considered that the battery collector fails, and the AC collector is immediately switched;

[0035] Or the battery is collected 6 seconds after the paddle, the main control judges whether the blade angle change is less than 30°, if yes, it is considered that the battery is collected, and immediately switch to AC paddle collection;

[0036] Switch to AC paddle collection, the main control DO interface circuit outputs high level, and the relay DA acts, and starts AC paddle collection.

[0037] The application can be collected through AC paddle under the condition of battery paddle failure, as long as the AC paddle supply voltage is normal, through circuit modification and software optimization, the malignant accidents such as fan overspeed, machine burning and machine falling are avoided, and the last safety protection is provided for the DC variable pitch system.

[0038] In a certain wind field, when the fan is in full power state, the main shaft overspeed module misoperation causes the safety chain to be disconnected, the main control starts the battery paddle collection, and the battery paddle collection fails due to the low temperature of the variable pitch system battery, the battery paddle collection fails due to the battery paddle collection failure, the fan overspeed safety chain is disconnected, and the on-grid breaker trips and dumps the load, from the fan starting battery paddle collection failure to the fan falling machine, only 46 seconds.

Claims

1. A control circuit for switching from a battery pitch system to an AC pitch system in case of a battery pitch failure, characterized in that The master DO interface circuit comprises a DO interface and a coil of a relay DA connected with the DO interface, the reset voltage circuit connects the reset circuit through the normally open node of the relay DA, and the master rpm-ok signal circuit connects the direct current variable pitch system through the normally closed node of the relay DA. The reset voltage circuit comprises a personal safety chain, a yaw reverse switch, a yaw forward switch, a vibration switch, a main shaft overspeed switch, a gearbox overspeed switch and a master internal safety switch connected in sequence, the personal safety chain comprises a blade maintenance switch, a frequency converter emergency stop switch and a cabin emergency stop switch connected in sequence, the blade maintenance switch and the yaw reverse switch output the reset voltage through the normally open node of the relay DA and connect the reset circuit, the cabin emergency stop switch is connected with a 24V voltage, and the master internal safety switch is connected with the coil of the relay K11.8 and the coil of the relay K11.9 through the normally closed node of the relay K11.8 and the normally closed node of the relay K11.9 respectively. The reset circuit comprises the relay K16.2, the relay K16.4 and the relay K16.6, the A2 end of the coil of the relay K16.2, the A2 end of the coil of the relay K16.4 and the A2 end of the coil of the relay K16.6 are connected with an N-UPS signal, the A1 end of the coil of the relay K16.2, the A1 end of the coil of the relay K16.4 and the A1 end of the coil of the relay K16.6 are connected with a 230V-UPS signal through a switch, the normally open node 3 of the relay K16.2 and the normally open node 3 of the relay K16.4 are connected with a +24V OUT signal, the normally open node 4 of the relay K16.2 is connected with a 103 signal interface through the normally open node of the relay K11.8, and the 103 signal interface is connected with the normally open node of the relay DA. The master rpm-ok signal circuit comprises a generator overspeed module, the normally closed node of the relay DA and the normally closed node of the relay K40.5, the output end 26.9 of the generator overspeed module is connected with a HUB signal through the normally closed node of the relay DA and the normally closed node of the relay K40.5, and the output end 26.8 of the generator overspeed module is also connected with the HUB signal. The master DO interface circuit further comprises a master PLC and a freewheeling diode, the DO interface of the master PLC is connected with one end of the coil of the relay DA and one end of the freewheeling diode respectively, and the other end of the coil of the relay DA and the other end of the freewheeling diode are grounded.

2. The control circuit for battery-to-AC failover of a pitch system of claim 1, wherein, The reset voltage is 24V.

3. The control circuit for battery-to-AC failover of a pitch system of claim 1, wherein, After the relay DA is turned on, the 103 signal interface outputs a high level to start the alternating current variable pitch.

4. The control circuit for battery-to-AC failover of a pitch system of claim 1, wherein, Specifically, 5. A control method of a control circuit that switches from a battery pitch system to an AC pitch system in the event of a battery pitch system failure, according to claim 1, characterized by, After the battery variable pitch is started for x seconds, the master PLC judges whether the blade angle changes by less than m°, if yes, it is considered that the battery variable pitch fails, and the alternating current variable pitch is switched immediately. ​ Or start battery pitch y seconds, the master PLC determines whether the blade angle change is less than n °, if so, the battery pitch is considered to fail, immediately switch to AC pitch; Switch to AC pitch, the master DO interface circuit output high level, relay DA action, start AC pitch.

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