WO2020232995A1

WO2020232995A1 - Power factor correction circuit and air conditioner

Info

Publication number: WO2020232995A1
Application number: PCT/CN2019/117017
Authority: WO
Inventors: 鲍殿生
Original assignee: 广东美的制冷设备有限公司
Priority date: 2019-05-17
Filing date: 2019-11-11
Publication date: 2020-11-26
Also published as: JP2022534367A

Abstract

A power factor correction circuit and an air conditioner. The power factor correction circuit comprises: a power factor correction module (10), wherein an alternating-current input end of the power factor correction module (10) is connected to an alternating-current power source, and is used for rectifying the alternating-current power source into a direct-current output; a switch driving module connected to a driving input end of the power factor correction module (10) and used for outputting a switching signal to the power factor correction module (10); a control module (30) connected to the switch driving module and used for controlling the opening or closing of a driving output of the switch driving module; a Hall current sensor (40) arranged on an alternating-current input side of the power factor correction module (10); and a driving protection module (50) connected to the Hall current sensor (40) and the control module (30) and used for determining, according to a relationship between a sampled signal and a corresponding first safety threshold, whether to output a protection signal to the control module (30). By means of the solution, whether a rectifier is abnormal can be detected more directly, and when it is determined that the rectifier is abnormal, corresponding abnormal components can be determined under different working conditions.

Description

Power factor correction circuit and air conditioner

This application requires that it be submitted to the Chinese Patent Office on May 17, 2019, the application number is "201910415198.2", the invention title is "Power factor correction circuit and air conditioner", and the Chinese Patent Office, application number on May 17, 2019 The priority of the Chinese patent application named "201920710867.4" and the invention title is "Power Factor Correction Circuit and Air Conditioner", the entire content of which is incorporated into this application by reference.

Technical field

This application relates to the technical field of air conditioners, and specifically to a power factor correction circuit and an air conditioner.

Background technique

In related technologies, the power factor correction circuit (ie PFC circuit) uses high-power MOS (metal-oxide-semiconductor) switching technology as the main power device to replace IGBT (insulated gate bipolar transistor) devices, and uses MOS with low on-resistance The characteristic replaces the constant characteristic of IGBT conduction voltage drop to realize the reduction of power consumption at low and medium power, so as to reduce the power consumption of the air conditioner.

Four switch tubes are used to form a power factor correction module, and two half-bridge drive chips are used to drive. One of the drive chips has a protection function and is combined with a sampling resistor for overcurrent detection. If a large current is detected, the four switches are triggered to close The driver output is used for over-current protection, but the scheme has the following defects:

As shown in Figure 1, the existing protection scheme can only detect when the upper and lower Q1 and Q3 are abnormal, or the upper and lower Q2 and Q4 are abnormal. In practical applications, the upper and lower switch tubes can be detected by the switch drive module itself. The built-in interlock protection circuit makes it difficult for the upper and lower bridge arms to pass through, so the probability of occurrence of the fault corresponding to this protection scheme is very low, and the practicability is relatively poor.

Summary of the invention

This application aims to solve at least one of the technical problems existing in the prior art or related technologies.

To this end, an object of the present application is to provide a power factor correction circuit.

Another object of the application is to provide an air conditioner.

In order to achieve the above objective, according to an embodiment of the first aspect of the present application, a power factor correction circuit is provided, which includes a power factor correction module that receives a power supply signal, the power factor correction module includes a switch tube, and the switch tube Is configured to control the power supply signal to supply power to the load; a switch drive module, connected to the drive input end of the power factor correction module, for outputting a switch signal to the power factor correction module; a control module, connected to the switch The drive module is used to control the switch drive module to turn on the output of the switch signal or turn off the output of the switch signal; the current sensor, which may specifically be a Hall current sensor, is set on the input side of the power factor correction module to collect Input current, and determine the input current as a sampling signal; drive a protection module, connected with the Hall current sensor and the control module, if the sampling signal is greater than a first safety threshold, output to the control module The protection signal is used to trigger the control module to turn off the output of the switch drive module.

In this technical solution, a Hall current sensor is set at the AC input of the power factor correction module. Based on the set position, the Hall current sensor collects the input current or output current of the power factor correction module, and converts the current into a sampling signal On the output drive protection module, the drive protection module detects whether there is an over-current phenomenon, so that when an over-current phenomenon is detected, the control stops outputting the switching signal to the power factor correction module. On the one hand, because the Hall current sensor does not Make electrical contact with the circuit under test, which can not consume the power of the power supply under test, so it does not affect the high-efficiency and low-power control of the frequency conversion equipment. On the other hand, because the Hall current sensor directly collects the input current of the power factor correction module, When the power factor correction module performs different functional operations, the corresponding different current flow paths can be detected by the Hall current sensor for circuit abnormality, so it can more directly detect whether the rectifier is abnormal, and when determining the abnormality, the The corresponding abnormal component can be determined under the working conditions. Compared with the prior art scheme of using a protective drive chip combined with a sampling resistor for overcurrent detection, it has less limitation and is more targeted and practical.

The first safety threshold is the safety threshold of the input terminal voltage.

Among them, the Hall current sensor is a sensor that uses the Hall effect to convert a large current into a second small sampling signal, and combines with an operational amplifier to amplify the small sampling signal into a standard voltage, which means that the Hall current sensor outputs a sampling signal to the outside. , And compare it with the built-in safety threshold of the drive protection module, and determine whether there is a short circuit overcurrent phenomenon in the circuit according to the comparison result. Since the Hall current sensor can measure both AC and DC, it can be set in power factor correction The AC input side of the module can also be set on the DC output side of the power factor correction module.

In the above technical solution, it further includes: a sampling resistor, which is arranged at the negative output terminal of the power factor correction module and connected to the drive protection module. The drive protection module detects a voltage drop on the sampling resistor. When the second safety threshold is exceeded, the protection signal is output to the control module.

In this technical solution, a Hall current sensor is connected in series on the AC side of the power factor correction module to detect the current on the AC side, and then the sampling signal output by the sensor is used as the input signal to drive the protection module, combined with the power A sampling resistor is connected in series with the negative output terminal of the factor correction module. The voltage detected by the sampling resistor is also input to the drive protection module. When either of the two input voltages exceeds the preset voltage of the current detection and drive protection module, the current will be triggered Detect and drive the protection of the protection module and turn off the power factor correction module, so that the detection function of overcurrent phenomenon can be realized on both the input and output sides.

The second safety threshold is the voltage safety threshold of the negative output terminal of the power factor correction module.

In any one of the above technical solutions, it further includes: a reactor arranged between the power factor correction module and the AC power source; a zero-crossing detection module arranged between the live wire end and the neutral wire end of the AC power source, And connected to the control module, the zero-crossing detection module is used to collect the zero-crossing detection signal between the live terminal and the neutral terminal; the control module is also used to: according to the zero-crossing detection module The output zero-crossing detection signal determines the phase state of the AC power source to output a switch control signal to the switch drive module according to the phase state to control charging of the reactor, and the AC power source is used to output all The power supply signal.

In this technical solution, the reactor is arranged between the AC input end of the power factor correction module and the AC power source. When the AC power source performs AC output, the reactor can convert the electrical energy supplied from the AC power source into magnetic energy for energy storage , And can realize the boost of PFC circuit and the improvement of power factor by releasing this energy.

Specifically, by setting a zero-crossing detection module between the live wire and the neutral wire, the zero-crossing detection module can determine the real-time phase of the AC power supply, so as to drive different switching devices in the power factor correction module to perform switching operations according to different phase states, The rectification function or the power factor correction (PFC) function is realized respectively, so that the DC power supply of the load is realized based on the rectification function, or the AC side voltage and the AC side current are in phase consistency through PFC control.

In addition, there are many reasons for the over-current phenomenon, such as the circuit being disturbed, causing the control module to crash and reset, or the reactor short-circuit abnormality.

In any of the above technical solutions, the Hall current sensor is arranged between the AC power supply and the reactor; the drive protection module is further configured to: if it is detected that the sampling signal is greater than a first safety threshold , Output the protection signal to the control module to turn off the output of the switch drive module.

Among them, the Hall current sensor can be placed in any position of the live or neutral line of the reactor.

In any of the above technical solutions, the power factor correction module is formed by a first switching tube, a second switching tube, a third switching tube, and a fourth switching tube. The first switching tube and the second switching tube are arranged in the power The upper part of the factor correction module, the third switch tube and the fourth switch tube are arranged in the lower part of the power factor correction module, the first switch tube and the third switch tube are arranged on the left part of the power factor correction module, the second switch tube and the fourth switch tube are arranged on the left part of the power factor correction module. The switch tube is arranged at the right part of the power factor correction module. The first switch tube, the second switch tube, the third switch tube, and the fourth switch tube are connected in reverse parallel with a freewheeling diode to connect the The drain of the first switching tube is connected in series with the drain of the second switching tube, and the connection point is determined as the positive output terminal of the power factor correction module, and the source of the third switching tube is connected to the fourth switching tube. The source of the tube is connected in series, the connection point is determined as the negative output terminal, which is connected in series with the sampling resistor and then grounded, the source of the first switching tube is connected in series with the drain of the third switching tube, and Connect the connection point to the live terminal, connect the source of the second switching tube and the drain of the fourth switching tube in series, and connect the connection point to the neutral terminal.

Specifically, the first switching tube, the second switching tube, the third switching tube, and the fourth switching tube may all be MOSFETs (Metal-Oxide-Semiconductor Field-Effect TransIstor, metal oxide semiconductor field effect transistor, that is, MOS tube), For example, super junction MOSFET, or SiC-MOSFET.

The working mode of the MOS tube realizes the switch by controlling the on-off between the source and the drain by the gate, and the gate power is greater than the source power when it is turned on.

In this technical solution, by setting a power factor correction module composed of four switch tubes, combined with the control instructions output by the control module, the control circuit performs rectification operation or power factor correction operation respectively. When used as a component of the motor drive system, By alternately performing "power factor improvement action" and "synchronous rectification action" to boost the voltage to achieve the purpose of increasing the allowable limit of the motor speed, and in the working process, by adding a current transformer and a Hall to the circuit The current sensor is used to detect the operating current, and in the case of detecting an abnormal current, control the power factor correction module to stop working, and re-run after the abnormality is eliminated, thereby ensuring the safety of the motor driving process.

In this technical solution, by setting the Hall current sensor on the AC input end of the power factor correction module, current flows through the Hall current sensor regardless of whether the rectification operation or the power factor correction operation is performed, so that current flow is detected When passing through the Hall device, the device will output the corresponding voltage. According to the current value that the four switch tubes of the power factor correction module can withstand, set the protection required in the overcurrent detection unit built in the drive protection module or the Hall current sensor The first switching tube is connected in series with the second switching tube between the live wire and the neutral line, and the third switching tube is connected in series with the fourth switching tube between the live wire and the neutral line. When the first switching tube-the second switching tube Or when the third switching tube-the fourth switching tube have abnormal overcurrent, the current will output the corresponding voltage through the Hall current sensor and trigger the driving protection module, and then turn off the switching signal of the switching driving module, so as to protect the switching tube Over-current, when the over-current signal is released, the drive protection module will release the control of the over-current switch drive module to restore normal operation, so that during the rectification operation or the power factor correction process, the probability of failure can be achieved relatively high In order to achieve the purpose of improving the safety of the entire PFC circuit.

For the power factor correction circuit of the Hall current sensor and the sampling resistor, the voltage can be sampled based on the Hall current sensor and/or the sampling resistor in different current flow paths, and the detection result of the sampling voltage can be used to determine whether there is a short circuit. Therefore, the detection requirements of different combined flow paths of the first switching tube, the second switching tube, the third switching tube and the fourth switching tube in the power factor correction module can be met.

In any of the above technical solutions, the switch drive module includes a first switch drive module for driving the first switch tube and the third switch tube, and a first switch drive module for driving the second switch tube and the third switch tube. The second switch drive module of the fourth switch tube, wherein, if the drive protection module detects that the sampling signal is greater than the first safety threshold and/or the pressure drop is greater than the second safety threshold, the control is triggered The module turns off the drive output of the first switch drive module and the second switch drive module.

In this technical solution, the switch drive module includes a first switch drive module and a second switch drive module to realize the half-bridge drive of the H-bridge organizer.

In addition, those skilled in the art can understand that when the control module controls the switch drive module to stop driving output, it controls the first switch drive module and the second switch drive module to stop output at the same time, that is, the two switch drive modules have the same execution priority.

Specifically, the first switch tube and the third switch tube are driven by the first switch drive module, the second switch tube and the fourth switch tube are driven by the second switch drive module, the sampling signal output by the Hall current sensor and the voltage of the sampling resistor The sampling signals are all connected to the drive protection module. When the drive protection module detects that the voltage output by the Hall current sensor and the voltage sampling signal on the sampling resistor exceed the preset value, the first switch drive module and the second switch drive module will be forcibly turned off. Thereby protecting the four switch tubes.

Among them, the Hall current sensor is mainly used to detect when the current passes through the first switching tube and the second switching tube in turn, or when the current passes through the third switching tube and the fourth switching tube in turn, when a short circuit is abnormal, the sampling resistor is mainly used for Detection when an abnormal short circuit occurs when the current passes through the first switch tube and the third switch tube in sequence, or when the current passes through the second switch tube and the fourth switch tube in sequence.

Among them, those skilled in the art can understand that the priority of the protection signal generated based on the trigger of the Hall current sensor is the same as that of the protection signal generated based on the trigger of the sampling resistor. Any abnormality in any way will trigger the drive protection module, and the cause of overcurrent may be It is because the circuit is subject to electromagnetic or surge interference that causes the control module to crash and reset, or the reactor has a short circuit abnormality, etc.

In any of the above technical solutions, it further includes: a bus capacitor connected to the DC output terminal of the power factor correction module and arranged in parallel with the load driving module.

In any of the above technical solutions, the control module is further configured to: if the input voltage of the AC power supply is in a positive half cycle, control the output of the switch drive module to make the first switch tube and the second The switch signal that the four switch tubes are turned on, and bypasses the corresponding freewheeling diode; the control module is also used to: if the input voltage of the AC power supply is in the negative half cycle, control the switch drive module to output for making all The switching signal of the second switching tube and the third switching tube is bypassed by the corresponding freewheeling diode to realize synchronous rectification.

Among them, there is a freewheeling diode inside the first switching tube. The freewheeling diode is part of the PN junction existing between the source and drain of the first switching tube. The saturation voltage of the first switching tube (in the on state) The voltage between the drain and the source) is lower than the forward voltage drop of the freewheeling diode. As a result, compared with the current flowing in the parasitic diode, the voltage drop in the current flowing in the source and drain of the first switch tube is reduced, and the conduction loss can even be reduced. It is easy to understand that the current flowing in the first switching tube in the on state makes the conduction loss smaller than the current flowing in the freewheeling diode in the first switching tube in the off state. In addition, for other The second switching tube, the third switching tube, and the fourth switching tube are also applicable.

In this technical solution, low power consumption synchronous rectification can be realized by using the principle of low conduction voltage drop of MOS transistors and turning on the corresponding MOS transistors according to the phase state of the alternating current.

Specifically, the control module outputs a corresponding control signal according to the current alternating current phase detected by the zero-crossing detection module, and drives the corresponding switch tube to work.

In the related art, when performing synchronous rectification, during the positive half cycle of the AC power supply, the current passes through the Hall current sensor and the reactor, and then supplies power to the system through the freewheeling diode rectification of the first switch tube and the fourth switch tube. The voltage drop of the freewheeling diode is large, causing energy waste.

In this technical solution, at this time, the control module judges according to the zero-crossing detection module that at the beginning of the positive half cycle of the AC power supply, the current passes through the Hall current sensor and the reactor, and the output switching signal drives the first switching tube and the fourth switching tube to conduct. , The current flowing through the first switch tube and the freewheeling diode on the fourth switch tube of the sampling resistor flows through the MOS tube, and the low conduction characteristic of the MOS tube is used to bypass the freewheeling diode, thereby reducing conduction loss. Similarly, in the negative half cycle of the AC power supply, the control module controls to turn on the second switching tube and the third switching tube, so that the four MOS tubes realize the synchronous rectification function. In the synchronous rectification process, the Hall current sensor and the sampling resistor The current detection on the device detects whether there is an overcurrent phenomenon.

In any of the above technical solutions, the control module is further configured to: if the input voltage of the AC power supply is in a positive half cycle, control the third switching tube and the third switching tube according to the zero-crossing detection signal and the switching signal. The fourth switching tube is turned on and off, the third switching tube is turned on with the fourth switching tube to charge the reactor, and the third switching tube and the fourth switching tube are turned off, The first switching tube is turned on, and the reactor supplies power to the load; the control module is also used for: if the input voltage of the AC power supply is in the negative half cycle, according to the zero-crossing detection signal and the switching signal Control the opening and closing of the third switching tube and the fourth switching tube, the third switching tube and the fourth switching tube are turned on to charge the reactor, and turning off the third switching tube With the fourth switching tube, the second switching tube is driven to conduct, and the reactor supplies power to the load to realize power factor correction.

In this technical solution, when the circuit is used for PFC operation, when the input is in the positive half cycle of the AC power supply, the control module drives the third switch tube and the fourth switch tube to conduct according to the zero-crossing detection signal to conduct the reactor Charging, in the charging process, by detecting the current on the Hall current sensor to determine whether there is a short circuit, when the third switch tube and the fourth switch tube are turned off, the control module drives the first switch tube to turn on, and the reactor stores the The electric energy will be released to the subsequent circuit through the first switch tube to supply power to the bus capacitor and load (such as the motor). When the input is in the negative half cycle of the AC power supply, the control module drives the third switch tube and the fourth switch tube according to the zero-crossing detection signal. The switching tube is turned on to charge the reactor. When the third switching tube and the fourth switching tube are turned off, the control module drives the second switching tube to open, and the electric energy stored in the reactor will be released to the subsequent circuit through the second switching tube , To supply power to the bus capacitor and load (such as a motor), by releasing the energy accumulated in the reactor to the bus capacitor, the DC voltage of the bus capacitor is boosted, so that the short-circuit current can be passed, reducing the distortion of the current waveform and making the current The waveform is close to a sine wave, which can improve the power factor of the PFC circuit. Furthermore, by calculating the pulse width of the third switching tube or the first switching tube according to the bus voltage of the load, the duration of the short-circuit current in the PFC circuit can be reasonably adjusted. The number of pulse changes reasonably controls the turn-on/turn-off times of each switch, which can reduce the conduction loss of the switching unit, reduce switching loss, and improve efficiency.

In any one of the above technical solutions, it further includes: a bus capacitor, one end of the bus capacitor is connected to the positive output terminal, the other end of the bus capacitor is grounded, and the switch drive module outputs the switching signal through the The AC power supply charges the bus capacitance or discharges the bus capacitance, the switch drive module does not output the switching signal, and the bus capacitance is discharged.

In any one of the above technical solutions, it further includes: a load drive module connected to the DC output terminal of the power factor correction module and configured to receive the DC output of the power factor correction module to supply power to the load; DC bus voltage The detection module is connected to the DC output terminal of the power factor correction module and is arranged in parallel with the load drive module for detecting the DC bus voltage.

In this technical solution, in the application scenario where the load is a motor, the load drive module is used to invert a regulated DC into a three-phase AC output to achieve power supply to the motor. Combined with the setting of the DC bus voltage detection module, The detection of the DC output bus voltage of the factor correction module and the detection of the input voltage control the switching state of each switch tube in the power factor correction module and the pulse width when each switch tube is turned on.

In any of the above technical solutions, the control module is also connected to the load drive module for outputting an inverter control signal to the load drive module.

According to an embodiment of the second aspect of the present application, there is provided an air conditioner including: the power factor correction circuit as described in the technical solution of the first aspect of the present application.

Specifically, the power factor correction circuit is applied to the motor drive system of the compressor, by detecting whether an overcurrent phenomenon occurs in the circuit, so as to prevent the motor from rotating too fast when the overcurrent occurs, causing the compressor to demagnetize.

The additional aspects and advantages of this application will be given in the following description, and some will become obvious from the following description, or be understood through the practice of this application.

Description of the drawings

The above and/or additional aspects and advantages of the present application will become obvious and easy to understand from the description of the embodiments in conjunction with the following drawings, in which:

Figure 1 shows a schematic diagram of a power factor correction circuit in the related art;

Fig. 2 shows a schematic diagram of a power factor correction circuit according to an embodiment of the present application.

Detailed ways

In order to be able to understand the above objectives, features and advantages of the application more clearly, the application will be further described in detail below in conjunction with the accompanying drawings and specific implementations. It should be noted that the embodiments of the application and the features in the embodiments can be combined with each other if there is no conflict.

In the following description, many specific details are set forth in order to fully understand this application. However, this application can also be implemented in other ways different from those described here. Therefore, the scope of protection of this application is not covered by the specific details disclosed below. Limitations of the embodiment.

Example one

As shown in FIG. 2, the power factor correction circuit according to an embodiment of the present application is suitable for air conditioners and includes: a power factor correction module 10 for receiving a power supply signal, the power factor correction module 10 includes a switch tube, and the switch The tube is configured to control the power supply signal to supply power to the load; the switch drive module is connected to the drive input end of the power factor correction module 10 for outputting a switch signal to the power factor correction module 10; the control module 30 is connected To the switch drive module, it is used to control the switch drive module to turn on the output of the switch signal or turn off the output of the switch signal; the Hall current sensor 40 is arranged on the AC input side of the power factor correction module 10 to Collect the input current, and determine the input current as a sampling signal; drive the protection module 50, which is connected to the Hall current sensor 40 and the control module 30, if the sampling signal is greater than the first safety threshold, The control module 30 outputs a protection signal, and the protection signal is used to trigger the control module 30 to turn off the output of the switch driving module.

In this embodiment, a Hall current sensor 40 is provided at the AC input end of the power factor correction module 10. The Hall current sensor 40 collects the input current or output current of the power factor correction module 10 based on the set position, and combines the current It is converted into a sampling signal and output to the drive protection module 50, so that the drive protection module 50 detects whether an over-current phenomenon occurs, so that when an over-current phenomenon is detected, the control stops outputting the switching signal to the power factor correction module 10. Because the Hall current sensor 40 does not make electrical contact with the circuit under test, it does not consume the power of the power supply under test, and therefore does not affect the high-efficiency and low-power control of the frequency conversion equipment. On the other hand, because the Hall current sensor 40 directly collects power The input terminal current of the factor correction module 10 is connected to the live and neutral terminal N of the AC power supply, so it can be more directly detected whether the rectifier is abnormal, and when the abnormality is determined, it can be used under different working conditions. Determining the corresponding abnormal components is less limited than the prior art that uses a driver chip with protection function combined with a sampling resistor Rs to perform overcurrent detection, and is more targeted and practical.

Among them, the Hall current sensor 40 is a sensor that uses the Hall effect to convert a large current into a second small sampling signal, and combines with an operational amplifier to amplify the small sampling signal into a standard voltage, that is, the Hall current sensor 40 outputs externally Sampling the signal and comparing it with the built-in safety threshold of the drive protection module 50. According to the result of the comparison, determine whether there is a short circuit or overcurrent phenomenon in the circuit. Since the Hall current sensor 40 can measure both AC and DC, it can be set The AC input side of the power factor correction module 10 may also be arranged on the DC output side of the power factor correction module 10.

Example two

As shown in FIG. 2, on the basis of setting the Hall current sensor 40, in the above embodiment, it further includes: a sampling resistor Rs, which is arranged at the negative output end of the power factor correction module 10 and connected to the drive The protection module 50 is configured to output the protection signal to the control module 30 when the drive protection module 50 detects that the voltage drop on the sampling resistor Rs exceeds a second safety threshold.

In this embodiment, a Hall current sensor 40 is connected in series on the AC side of the power factor correction module 10 to detect the current on the AC side, and then the sampling signal output by the sensor is used as the input signal for driving the protection module 50, Combined with the sampling resistor Rs connected in series with the negative output terminal of the power factor correction module 10, the voltage detected by the sampling resistor Rs is also input to the drive protection module 50. When either of the two input voltages exceeds the preset value of the current detection and drive protection module 50 When the voltage is set, the protection of the current detection and driving protection module 50 will be triggered and the power factor correction module 10 will be turned off.

In any of the above embodiments, it further includes: a reactor L1, which is arranged between the power factor correction module 10 and the AC power source; and a zero-crossing detection module 60, which is arranged on the live wire end L and the neutral wire of the AC power source Between terminals N and connected to the control module 30, the zero-crossing detection module 60 is used to collect the zero-crossing detection signal between the live terminal L and the neutral terminal N; the control module 30 also Used for: determining the phase state of the AC power supply according to the zero-crossing detection signal output by the zero-crossing detection module 60, so as to output a switch control signal to the switch drive module according to the phase state, so as to control the reactor L1 is charged.

In this embodiment, by disposing the reactor L1 between the AC input end of the power factor correction module 10 and the AC power source, when the AC power source performs AC output, the reactor L1 can convert the electrical energy supplied from the AC power source into magnetic energy. As energy storage, and can realize the boost of PFC circuit and the improvement of power factor by releasing this energy.

Specifically, by setting the zero-crossing detection module 60 between the live wire and the neutral wire, the zero-crossing detection module 60 determines the real-time phase of the AC power source, so as to drive different switching devices in the power factor correction module 10 according to different phase states. Switch operation to realize the rectification function or power factor correction (PFC) function respectively, thereby realizing the DC power supply at the load side based on the rectification function, or through PFC control, so that the AC side voltage and the AC side current are in phase.

In addition, there are many reasons for the over-current phenomenon, for example, the circuit is disturbed and the control module 30 crashes and resets, or the reactor L1 is abnormally short-circuited.

Example three

As shown in FIG. 2, in any of the above embodiments, the power factor correction module 10 is formed by a first switching tube Q1, a second switching tube Q2, a third switching tube Q3, and a fourth switching tube Q4. A switch tube Q1 and a second switch tube Q2 are arranged on the upper part of the power factor correction module 10, the third switch tube Q3 and the fourth switch tube Q4 are arranged on the lower part of the power factor correction module 10, the first switch tube Q1 and the third switch The tube Q3 is arranged at the left part of the power factor correction module 10, the second switching tube Q2 and the fourth switching tube Q4 are arranged at the right part of the power factor correction module 10, the first switching tube Q1, the second switching tube Q2 , The third switching tube Q3 and the fourth switching tube Q4 are connected in reverse parallel with a freewheeling diode, the drain of the first switching tube Q1 and the drain of the second switching tube Q2 are connected in series, and The connection point is determined as the positive output terminal of the power factor correction module, the source of the third switching tube Q3 and the source of the fourth switching tube Q4 are connected in series, and the connection point is connected in series with the sampling resistor Rs and grounded , Connect the source of the first switching tube Q1 and the drain of the third switching tube Q3 in series, and connect the connection point to the live terminal L, and connect the source of the second switching tube Q2 to the The drain of the fourth switch tube Q4 is connected in series, and the connection point is connected to the neutral terminal N.

Specifically, the first switching tube Q1, the second switching tube Q2, the third switching tube Q3, and the fourth switching tube Q4 can all be MOSFT (Mta-Oxid-Smicoductor Fid-ffct TrasIstor, metal oxide semiconductor field effect transistors, namely MOS tube), such as super junction MOSFT or SiC-MOSFT.

In this embodiment, by setting the power factor correction module 10 composed of four switch tubes, combined with the control instructions output by the control module 30, the control circuit performs the rectification operation or the power factor correction operation respectively, as a component of the motor drive system At the same time, the voltage is boosted by alternately performing "power factor improvement actions" and "synchronous rectification actions" to achieve the purpose of increasing the allowable limit of the motor speed, and in the working process, by adding current transformers and The Hall current sensor is used to detect the operating current, and when an abnormal current is detected, the power factor correction module 10 is controlled to stop working and restart after the abnormality is eliminated, so as to ensure the safety of the motor driving process.

In this embodiment, by setting the Hall current sensor 40 at the AC input end of the power factor correction module 10, no matter whether the rectification operation or the power factor correction operation is being performed, current flows through the Hall current sensor 40, so that when detecting When a current flows through the Hall device, the device will output the corresponding voltage. According to the current value that the four switch tubes of the power factor correction module 10 can withstand, the overcurrent detection in the drive protection module 50 or the Hall current sensor 40 The voltage value to be protected is set in the unit. The first switch tube Q1 and the second switch tube Q2 are connected in series between the live wire and the neutral line, and the third switch tube Q3 and the fourth switch tube Q4 are connected in series between the live wire and the neutral line. When the first switching tube Q1-the second switching tube Q2, or the third switching tube Q3-the fourth switching tube Q4 has abnormal overcurrent, the current will output the corresponding voltage through the Hall current sensor 40 and trigger the drive protection module 50, Then the switch signal of the switch drive module is turned off to protect the overcurrent to the switch tube. When the overcurrent signal is released, the drive protection module 50 will release the control of the overcurrent switch drive module to resume normal operation, so as to resume normal operation. In the process, or in the power factor correction process, timely and effective detection of faults with relatively high probability can be realized, so as to achieve the purpose of improving the safety of the entire PFC circuit.

For the power factor correction circuit of the Hall current sensor 40 and the sampling resistor Rs, the voltage can be sampled based on the Hall current sensor 40 and/or the sampling resistor Rs in different current flow paths, and the voltage can be determined according to the detection result of the sampling voltage Whether there is a short-circuit phenomenon, it can meet the detection requirements of different combined flow paths of the first switching tube Q1, the second switching tube Q2, the third switching tube Q3, and the fourth switching tube Q4 in the power factor correction module 10.

In any of the above embodiments, the switch drive module includes a first switch drive module 202 for driving the first switch tube Q1 and the third switch tube Q3, and a first switch drive module 202 for driving the second switch The second switch drive module 204 of the tube Q2 and the fourth switch tube Q4, wherein, if the drive protection module 50 detects that the sampling signal is greater than the first safety threshold and/or the pressure drop is greater than the second safety Threshold value, the control module 30 is triggered to turn off the driving output of the first switch driving module 202 and the second switch driving module 204.

In this embodiment, the switch drive module includes a first switch drive module 202 and a second switch drive module 204 to realize the half-bridge drive of the H-bridge organizer.

In addition, those skilled in the art can understand that when the control module 30 controls the switch drive module to stop driving output, it controls the first switch drive module 202 and the second switch drive module 204 to stop output at the same time, that is, the two switch drive modules have The same execution priority.

In any of the above embodiments, it further includes: a bus capacitor E, connected to the DC output terminal of the power factor correction module 10 and arranged in parallel with the load driving module 70.

Example four

As shown in FIG. 2, in any of the above embodiments, the Hall current sensor 40 is arranged between the AC power supply and the reactor L1; the drive protection module 50 is also used to: If the sampling signal is greater than the first safety threshold, the protection signal is output to the control module 30 to turn off the output of the switch driving module.

Wherein, the Hall current sensor 40 can be placed at any position of the live wire or the neutral wire of the reactor L1 in series.

In this embodiment, by setting the Hall current sensor 40 at the AC input end of the power factor correction module 10, no matter whether the rectification operation or the power factor correction operation is being performed, current flows through the Hall current sensor 40, so that when detecting When a current flows through the Hall device, the device will output the corresponding voltage. According to the current value that the four switch tubes of the power factor correction module 10 can withstand, the overcurrent detection in the drive protection module 50 or the Hall current sensor 40 The voltage value to be protected is set in the unit. The first switch tube Q1 and the second switch tube Q2 are connected in series between the live wire and the neutral line, and the third switch tube Q3 and the fourth switch tube Q4 are connected in series between the live wire and the neutral line. When the first switching tube Q1-the second switching tube Q2 or the third switching tube Q3-the fourth switching tube Q4 has abnormal overcurrent, the current will output the corresponding voltage through the Hall current sensor 40 and trigger the drive protection module 50, and then Turn off the switching signal of the switch drive module to protect the overcurrent to the switch tube. When the overcurrent signal is released, the drive protection module 50 will release the control of the overcurrent switch drive module to resume normal operation, thus during the rectification operation process In the process of power factor correction, timely and effective detection of faults with relatively high probability can be realized, so as to achieve the purpose of improving the safety of the entire PFC circuit.

The first switch tube Q1 and the third switch tube Q3 are driven by the first switch drive module 202, the second switch tube Q2 and the fourth switch tube Q4 are driven by the second switch drive module 204, and the sampling signal output by the Hall current sensor 40 is sum The voltage sampling signals of the sampling resistor Rs are all connected to the drive protection module 50. When the drive protection module 50 detects that the voltage output by the Hall current sensor 40 and the voltage sampling signal on the sampling resistor Rs exceed the preset value, the first switch will be forcibly turned off The driving module 202 and the second switch driving module 204 protect the four switch tubes.

Among them, the Hall current sensor 40 is mainly used to detect when the current passes through the first switching tube Q1 and the second switching tube Q2 in sequence, or when the current passes through the third switching tube Q3 and the fourth switching tube Q4 in sequence, when a short circuit abnormality occurs. The sampling resistor Rs is mainly used to detect when the current passes through the first switching tube Q1 and the third switching tube Q3 in sequence, or when the current passes through the second switching tube Q2 and the fourth switching tube Q4 in sequence, when a short circuit abnormality occurs.

Among them, those skilled in the art can understand that the protection signal generated based on the trigger of the Hall current sensor 40 has the same priority as the protection signal generated based on the trigger of the sampling resistor Rs. An abnormality in any one way will trigger the drive protection module 50. The cause of the current flow may be that the circuit is subject to electromagnetic or surge interference, causing the control module 30 to crash and reset, or the reactor L1 has a short circuit abnormality, and so on.

Example five

In any of the above embodiments, the control module 30 is further configured to: if the input voltage of the AC power supply is in a positive half cycle, control the output of the switch drive module to make the first switch tube Q1 and the The switch signal that the fourth switch tube Q4 is turned on, and bypasses the corresponding freewheeling diode; the control module 30 is also used to: if the input voltage of the AC power supply is in the negative half cycle, control the switch drive module to output The switching signal used to make the second switching tube Q2 and the third switching tube Q3 conduct, and bypassing the corresponding freewheeling diode to realize synchronous rectification.

Among them, there is a freewheeling diode inside the first switching tube Q1. The freewheeling diode is a part of the P junction that exists between the source and drain of the first switching tube Q1. The saturation voltage of the first switching tube Q1 (connected to The voltage between the drain and the source in the on state is lower than the forward voltage drop of the freewheeling diode. Therefore, compared with the current flowing in the parasitic diode, the voltage drop of the current flowing in the source and drain of the first switching tube Q1 is reduced, and the conduction loss can even be reduced. It is easy to understand that the current flowing in the first switching tube Q1 in the on state makes the conduction loss smaller than the current flowing in the freewheeling diode in the first switching tube Q1 in the off state. In addition, for Other second switching tubes Q2, third switching tubes Q3, and fourth switching tubes Q4 are also applicable.

In this embodiment, the low-power synchronous rectification can be realized by using the principle of the low conduction voltage drop of the MOS transistor and turning on the corresponding MOS transistor according to the phase state of the alternating current.

Specifically, the control module 30 outputs a corresponding control signal according to the current alternating current phase detected by the zero-crossing detection module 60, and drives the corresponding switch tube to work.

In the related art, when performing synchronous rectification, during the positive half cycle of the AC power supply, the current passes through the Hall current sensor 40 and the reactor L1, and then the system is rectified by the freewheeling diodes of the first switching tube Q1 and the fourth switching tube Q4. At this time, due to the large voltage drop of the freewheeling diode, energy is wasted.

In this embodiment, at this time, the control module 30 judges according to the zero-crossing detection module 60 that at the beginning of the positive half cycle of the AC power supply, the current passes through the Hall current sensor 40 and the reactor L1, and outputs a switching signal to drive the first switching tube Q1 and the second The four switching tube Q4 is turned on, so that the current flowing through the first switching tube Q1, the sampling resistor Rs and the freewheeling diode on the fourth switching tube Q4 flows through the MOS tube, and the freewheeling diode is bypassed by the low conduction characteristic of the MOS tube , Thereby reducing the conduction loss. Similarly, in the negative half cycle of the AC power supply, the control module 30 controls to turn on the second switching tube Q2 and the third switching tube Q3, so that the four MOS tubes can realize the synchronous rectification function. 40 and the current detection on the sampling resistor Rs to detect whether there is an overcurrent phenomenon.

Example Six

In any of the above embodiments, the control module 30 is further configured to: if the input voltage of the AC power supply is in a positive half cycle, control the third switch tube according to the zero-crossing detection signal and the switch signal Q3 and the fourth switching tube Q4 are switched on and off, and the third switching tube Q3 and the fourth switching tube Q4 are turned on to charge the reactor L1 and turn off the third switching tube Q3 and The fourth switching tube Q4, the first switching tube Q1 are turned on, and the reactor L1 supplies power to the load; the control module 30 is also used to: if the input voltage of the AC power supply is in the negative half cycle, perform The zero-crossing detection signal and the switching signal control the opening and closing of the third switching tube Q3 and the fourth switching tube Q4, and the third switching tube Q3 and the fourth switching tube Q4 are turned on to connect The reactor L1 is charged, the third switching tube Q3 and the fourth switching tube Q4 are turned off, the second switching tube Q2 is driven to be turned on, and the reactor L1 supplies power to the load to achieve power factor Correction.

In this embodiment, when the circuit is used for PFC operation, when the input is in the positive half cycle of the AC power supply, the control module 30 drives the third switching tube Q3 and the fourth switching tube Q4 to be turned on according to the zero-crossing detection signal. The reactor L1 is charged. When the third switching tube Q3 and the fourth switching tube Q4 are turned off, the control module 30 drives the first switching tube Q1 to open, and the electric energy stored in the reactor L1 will be released to the subsequent stage through the first switching tube Q1 The circuit supplies power to the bus capacitor E and the load (such as a motor). When the input is in the negative half cycle of the AC power supply, the control module 30 drives the third switching tube Q3 and the fourth switching tube Q4 to conduct according to the zero-crossing detection signal, and react to the reactance. When the third switching tube Q3 and the fourth switching tube Q4 are turned off, the control module 30 drives the second switching tube Q2 to open, and the electric energy stored in the reactor L1 will be released to the subsequent circuit through the second switching tube Q2 , To supply power to the bus capacitor E and the load (such as a motor), by releasing the energy accumulated in the reactor L1 to the bus capacitor E, the DC voltage of the bus capacitor E is boosted, so that the short-circuit current can be used to reduce the current waveform Distortion makes the current waveform close to a sine wave, thereby improving the power factor of the PFC circuit. Furthermore, by calculating the pulse width of the third switching tube Q3 or the first switching tube Q1 according to the bus voltage of the load, the short circuit in the PFC circuit can be reasonably adjusted The duration of the current and the reasonable control of the turn-on/turn-off times of each switch according to the number of pulse changes can reduce the conduction loss of the switching unit, reduce the switching loss, and improve the efficiency.

In any of the above embodiments, it further includes: a bus capacitor E, one end of the bus capacitor E is connected to the positive output terminal, the other end of the bus capacitor E is grounded, and the switch driving module outputs the switching signal, The bus capacitor E is charged by the AC power source, or the bus capacitor E is discharged, the switch driving module does not output the switching signal, and the bus capacitor E is discharged.

In any of the above embodiments, it further includes: a load driving module 70, connected to the DC output terminal of the power factor correction module 10, and configured to receive the DC output of the power factor correction module 10 to supply power to the load; The DC bus voltage detection module (not shown in the figure) is connected to the DC output terminal of the power factor correction module 10 and is arranged in parallel with the load driving module 70 for detecting the DC bus voltage.

In this embodiment, in an application scenario where the load is a motor, the load drive module 70 is used to invert a regulated DC into a three-phase AC output to achieve power supply to the motor. Combined with the setting of the DC bus voltage detection module, The detection of the bus voltage of the DC output of the power factor correction module 10 and the detection of the input voltage control the switching state of each switching tube in the power factor correction module 10 and the pulse width when each switching tube is turned on.

In any of the above embodiments, the control module 30 is further connected to the load driving module 70 for outputting an inverter control signal to the load driving module 70.

An air conditioner according to an embodiment of the present application includes: the power factor correction circuit described in any one of the above embodiments.

Compared with the prior art, the embodiments disclosed in the technical solution of this application have at least the following beneficial effects:

(1) Since the Hall current sensor directly collects the input current of the power factor correction module, the different current flow paths corresponding to the power factor correction module when performing different functional operations can be detected by the Hall current sensor for circuit abnormality. It can more directly detect whether the rectifier is abnormal, and when the abnormality is determined, the corresponding abnormal component can be determined under different working conditions. Compared with the prior art, the driver chip with protection function combined with the sampling resistor for overcurrent The detection scheme has smaller limitations, and is more targeted and practical.

(2) A Hall current sensor is connected in series on the AC side of the power factor correction module to detect the current on the AC side, and then the sampling signal output by the sensor is used as the input signal to drive the protection module, combined with the power factor correction module A sampling resistor connected in series with the negative output terminal of the sampling resistor. The voltage detected by the sampling resistor is also input to the drive protection module. When either of the two input voltages exceeds the preset voltage of the current detection and drive protection module, the current detection and drive will be triggered The protection module protects and turns off the power factor correction module, so that the detection function of overcurrent phenomenon can be realized on both the input and output sides.

(3) For the power factor correction circuit of the Hall current sensor and the sampling resistor, the voltage can be sampled based on the Hall current sensor and/or the sampling resistor in different current flow paths, and whether the voltage is determined according to the detection result of the sampling voltage There is a short circuit phenomenon, so it can meet the detection requirements of different combined flow paths of the first switch tube, the second switch tube, the third switch tube, and the fourth switch tube in the power factor correction module.

The technical solution of the present application is described in detail above with reference to the drawings. A Hall current sensor is connected in series on the AC side of the power factor correction module to detect the current on the AC side, and then the sampling signal output by the sensor is used as the drive protection module. The input signal is combined with a sampling resistor connected in series with the negative output terminal of the power factor correction module. The voltage detected by the sampling resistor is also input to the drive protection module. When either of the two input voltages exceeds the preset of the current detection and drive protection module When the voltage is applied, the protection of the current detection and drive protection module will be triggered and the power factor correction module will be turned off.

Those skilled in the art should understand that the embodiments of the present application can be provided as methods, systems, or computer program products. Therefore, the present application may adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Moreover, this application may adopt the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program codes.

This application is described with reference to flowcharts and/or block diagrams of methods, equipment (systems), and computer program products according to the embodiments of this application. It should be understood that each process and/or block in the flowchart and/or block diagram, and the combination of processes and/or blocks in the flowchart and/or block diagram can be implemented by computer program instructions. These computer program instructions can be provided to the processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing equipment to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing equipment are generated It is a device that realizes the functions specified in one process or multiple processes in the flowchart and/or one block or multiple blocks in the block diagram.

These computer program instructions can also be stored in a computer-readable memory that can guide a computer or other programmable data processing equipment to work in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture including the instruction device. The device implements the functions specified in one process or multiple processes in the flowchart and/or one block or multiple blocks in the block diagram.

These computer program instructions can also be loaded on a computer or other programmable data processing equipment, so that a series of operation steps are executed on the computer or other programmable equipment to produce computer-implemented processing, so as to execute on the computer or other programmable equipment. The instructions provide steps for implementing functions specified in a flow or multiple flows in the flowchart and/or a block or multiple blocks in the block diagram.

It should be noted that in the claims, any reference signs located between parentheses should not be constructed as limitations on the claims. The word "comprising" does not exclude the presence of parts or steps not listed in the claims. The word "a" or "an" preceding a component does not exclude the presence of multiple such components. This application can be realized by means of hardware including several different components and by means of a suitably programmed computer. In the module claims that list several devices, several of these devices can be embodied in the same hardware item. The use of the words first, second, and third, etc. do not indicate any order. These words can be interpreted as names.

Although the preferred embodiments of the present application have been described, those skilled in the art can make additional changes and modifications to these embodiments once they learn the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications falling within the scope of the present application.

Obviously, those skilled in the art can make various changes and modifications to the application without departing from the scope of the claims of the application and its equivalent technologies, and the application also intends to include these changes and modifications.

Claims

A power factor correction circuit, which includes:

A power factor correction module that receives a power supply signal, the power factor correction module includes a switch tube configured to control the power supply signal to supply power to the load;

A switch drive module, connected to the drive input end of the power factor correction module, and used to output a switch signal to the power factor correction module;

The control module is connected to the switch drive module and is used to control the switch drive module to turn on the output of the switch signal or turn off the output of the switch signal;

A current sensor arranged on the input side of the power factor correction module to collect input current and determine the input current as a sampling signal;

The drive protection module is connected to the current sensor and the control module. If the sampling signal is greater than the first safety threshold, a protection signal is output to the control module, and the protection signal is used to trigger the control module to close the control module. The output of the switch drive module.
The power factor correction circuit according to claim 1, further comprising:

The sampling resistor is set at the negative output terminal of the power factor correction module and connected to the drive protection module. When the drive protection module detects that the voltage drop across the sampling resistor exceeds a second safety threshold, The control module outputs the protection signal.
The power factor correction circuit according to claim 2, further comprising:

The reactor is arranged between the power factor correction module and the AC power source;

The zero-crossing detection module is arranged between the live terminal and the neutral terminal of the AC power supply and is connected to the control module, and the zero-crossing detection module is used to collect between the live terminal and the neutral terminal The zero-crossing detection signal;

The control module is further configured to determine the phase state of the AC power supply according to the zero-cross detection signal output by the zero-cross detection module, so as to output a switch control signal to the switch drive module according to the phase state to control the The reactor is charged,

The AC power supply is used to output the power supply signal.
The power factor correction circuit according to claim 3, wherein:

The current sensor is arranged between the AC power source and the reactor;

The drive protection module is further configured to: if it is detected that the sampling signal is greater than a first safety threshold, output the protection signal to the control module to turn off the output of the switch drive module.
The power factor correction circuit according to claim 4, wherein:

The power factor correction module is formed by a first switching tube, a second switching tube, a third switching tube, and a fourth switching tube. The first switching tube, the second switching tube, the third switching tube and the The fourth switching tube is connected in reverse parallel with a freewheeling diode, the drain of the first switching tube is connected in series with the drain of the second switching tube, and the connection point is determined to be the anode of the power factor correction module The output terminal is connected in series with the source of the third switching tube and the source of the fourth switching tube, and the connection point is determined as the negative output terminal, which is connected in series with the sampling resistor and then grounded to connect the first switch The source of the tube is connected in series with the drain of the third switching tube, and the connection point is connected to the live terminal, the source of the second switching tube is connected in series with the drain of the fourth switching tube, and Connect the connection point to the neutral terminal.
The power factor correction circuit according to claim 5, wherein:

The switch drive module includes a first switch drive module for driving the first switch tube and the third switch tube, and a second switch for driving the second switch tube and the fourth switch tube Drive module,

Wherein, if the drive protection module detects that the sampling signal is greater than the first safety threshold and/or the pressure drop is greater than the second safety threshold, it triggers the control module to turn off the first switch drive module and the The drive output of the second switch drive module.
The power factor correction circuit according to claim 5, wherein:

The control module is further configured to: if the input voltage of the AC power supply is in a positive half cycle, control the switch drive module to output a switch signal for turning on the first switch tube and the fourth switch tube, And bypass the corresponding freewheeling diode;

The control module is further configured to: if the input voltage of the AC power supply is in a negative half cycle, control the switch drive module to output a switch signal for conducting the second switch tube and the third switch tube, And bypass the corresponding freewheeling diode to achieve synchronous rectification.
The power factor correction circuit according to claim 5, wherein:

The control module is further configured to: if the input voltage of the AC power supply is in a positive half cycle, control the opening and closing of the third switching tube and the fourth switching tube according to the zero-crossing detection signal and the switching signal, The third switching tube and the fourth switching tube are turned on to charge the reactor, the third switching tube and the fourth switching tube are turned off, and the first switching tube is turned on, The reactor supplies power to the load;

The control module is further configured to: if the input voltage of the AC power supply is in the negative half cycle, control the opening and closing of the third switching tube and the fourth switching tube according to the zero-crossing detection signal and the switching signal, The third switching tube and the fourth switching tube are turned on to charge the reactor, turning off the third switching tube and the fourth switching tube, and driving the second switching tube to be turned on , The reactor supplies power to the load to realize power factor correction.
The power factor correction circuit according to claim 5, further comprising:

Bus capacitor, one end of the bus capacitor is connected to the positive output terminal, the other end of the bus capacitor is grounded, the switch drive module outputs the switching signal, and the bus capacitor is charged through the AC power supply, or the The bus capacitance is discharged, the switch drive module does not output the switching signal, and the bus capacitance is discharged.
The power factor correction circuit according to any one of claims 1 to 8, further comprising:

A load driving module, connected to the DC output terminal of the power factor correction module, and used to receive the DC output of the power factor correction module to supply power to the load;

The control module is also connected to the load drive module for outputting an inverter control signal to the load drive module.
An air conditioner, comprising: the power factor correction circuit according to any one of claims 1 to 10.