11495results about "Dc-ac conversion without reversal" patented technology

The present invention relates to the field of fault diagnosis technology, specifically to a fault diagnosis method and system for a photovoltaic inverter, comprising the following steps: based on an operating status data set, analyzing a variety of inverter operating data, identifying the volatility of a variety of operating data, extracting statistical features and frequency domain features of the data, adjusting the detection threshold of abnormal data, and generating abnormal fluctuation detection parameters. In the present invention, the abnormal detection threshold is dynamically adjusted by analyzing the operating data, a more sensitive response is made to the data, the accuracy and response speed of the fault warning are improved, the time window segmentation and signal feature extraction are used to timely discover abnormal fluctuations, detect equipment damage or system failures, and the accuracy of fault type identification is improved by combining the comparison and analysis of data features. By analyzing the component types associated with various fault types, the efficiency and accuracy of locating faulty components are improved, and the reliability and economic benefits of the photovoltaic inverter are enhanced.

The present invention relates to the technical field of circuit control, and relates to a direct-current high-voltage generator regulation and control method and system based on intelligent feedback. A fuzzy control logic operation is performed on an output current flux value and an input voltage fluctuation factor of a load experimental object, so as to obtain the disturbance amplitude of a voltage fluctuation state for a current flux change trend; if a step-up transformer can execute a PID control technology by adjusting a transformation ratio, PID real-time adjustment parameters are calculated, and a crossover mutation operation of individuals is performed on the basis of a fitness function, so as to generate a first boost regulation and control scheme; and if the step-up transformer cannot execute the PID control technology by adjusting the transformation ratio, a calibrated state feedback controller is constructed on the basis of a state variable of the current step-up transformer and an adjustment signal output amplitude, so as to generate a second boost regulation and control scheme. The present invention achieves intelligent feedback regulation and control by independently analyzing components of direct-current high-voltage generators, improving the stability and accuracy of outputting high-voltage direct current.

The invention relates to the technical field of new energy grid-connected converter control, in particular to a grid-connected converter control method based on grid-following and grid-construction hybrid control, which flexibly adjusts the characteristic proportion of grid-following and grid-construction by constructing a self-adaptive hybrid synchronous control model, ensures the smooth and efficient grid-connected process, and improves the grid-connected efficiency. A voltage and current double-loop control model is constructed to accurately regulate and control output voltage and current, the high-standard electric energy quality requirement of a power grid for new energy power generation is met, meanwhile, power grid impedance estimation is introduced for virtual impedance control, and the anti-interference capability and the response speed of the system are further enhanced. In conclusion, according to the grid-connected converter control method based on grid following and grid construction hybrid control, the adaptability and stability of the system to the complex power grid environment are remarkably improved, and the overall operation efficiency and reliability of the system are improved.

Provided is a flying apparatus capable of effectively cooling a constituent device. A flying apparatus 10 comprises: an airframe base 14; a power supply unit; an arm 11 which extends from the airframe base 14 toward a periphery; a rotor 12 which is disposed on an end portion side of the arm 11; a motor 17 which rotationally drives the rotor 12; and a power converting unit 19 which converts electric power supplied from the power supply unit to the motor 17. The power converting unit 19 is included inside the arm 11 below a rotation range 24 of the rotor 12.

The invention discloses a VSG-based energy storage converter three-parameter coordinated adaptive control method, which comprises the following steps of: acquiring three-phase voltage and current of a VSG output port and three-phase voltage data of a grid-connected point, and calculating an output power difference, an output power change rate and a power grid angular frequency difference of the VSG; the power instruction is corrected by combining the power instruction and the power grid angular frequency difference, and the adjustment process of the VSG is divided into six stages according to a power fluctuation curve; the rotational inertia, the virtual damping and the virtual inductance are adjusted according to the power difference and the power change rate in the six stages; the virtual inductor is finely adjusted by combining the VSG output power difference and the output power change rate, and smooth transition of the virtual inductor and smooth adjustment of the power are achieved; the value of the virtual inductance is compared with the initial value of the virtual inductance, and the virtual impedance is subjected to initial value regression operation, so that the power equalization and the system stability of the parallel VSG are not influenced. The method has obvious effects on power oscillation suppression and dynamic performance improvement of the energy storage converter system based on the VSG.

The invention discloses a heat dissipation control method and system for stable operation of a photovoltaic inverter, and relates to the technical field of photovoltaic inverter control, and the method comprises the steps: collecting the multi-source data of heat dissipation equipment and elements in the use of the photovoltaic inverter; constructing a feature relation model and an LSTM neural network prediction model based on data acquisition; and through the constructed feature relation model and the LSTM neural network prediction model, analysis is carried out to compare different levels of heat dissipation power with the inverter efficiency improvement degree under different environment temperatures and power levels, a predicted temperature is formed, risk levels are divided, and the optimal heat dissipation level is determined. According to the method, the predicted temperature is graded by utilizing synchronous acquisition of multi-source data and constructing the feature relation model and the LSTM neural network prediction model, and the multi-mode heat dissipation strategy is formulated, so that the heat dissipation strategy is adaptively adjusted according to the state of the photovoltaic inverter to perform adaptive heat dissipation, and the heat dissipation efficiency is improved. And the heat dissipation effect of the photovoltaic inverter is further improved.

The invention relates to the technical field of inverter control, and discloses an inverter output power control method and device, equipment and a storage medium. The method comprises the following steps: performing power frequency fundamental wave extraction and multi-band band-pass filtering on acquired voltage and current sampling data; performing phase compensation, first coordinate transformation and positive and negative sequence decoupling operation on the filtered fundamental wave principal component data; on the basis of a synchronous phase angle and a power grid fundamental wave frequency obtained by positive and negative sequence decoupling operation, carrying out second coordinate transformation, moving average and harmonic power delay difference operation on three-phase current and voltage data of an alpha-beta coordinate system; performing multi-level power calculation, power capacity distribution, error characteristic evaluation and decoupling operation on the inversion fundamental component and the inversion harmonic component subjected to the difference operation; and performing output signal modulation on the inversion power control quantity of the decoupling operation based on the fundamental wave synchronization phase angle, and generating a power control result. According to the invention, the control performance of the inverter on the output power in actual operation is improved.

A passivity-based dual-mode integrated control method for a grid-connected inverter (GCI) is provided. In view of the insufficient robustness of the conventional single-mode GCI in a high-impedance and low-inertia weak grid, and the problem of wideband oscillation of the grid voltage and grid current or even system instability in nonlinear application scenarios such as grid structure / parameter variation, and plug-and-play of the inverter, the dual-mode integrated control method performs modeling on the GCI based on a port-controlled Hamiltonian (PCH) model, thereby obtaining integrated control with a weighted passivity-based feedback control law for the GCI based on a grid-following (GFL) mode and a grid-forming (GFM) mode. Based on the dual-mode integrated control method, the stable operation of the GCI in severe grid conditions with large fluctuation of the impedance, and desirable robustness of the GCI in nonlinear working scenarios can be ensured.

An electrical propulsion system for a vertical take-off and landing (VTOL) aircraft comprises an electrical motor assembly and an inverter assembly. The inverter assembly comprises a housing, a capacitor assembly, at least one printed circuit board assembly (PCBA), and a plurality of positioning pins. The capacitor assembly comprises a center hole, at least one capacitor, a capacitor housing having at least one busbar, and a plurality of through holes in the capacitor housing. The capacitor assembly and the at least one PCBA are positioned inside the housing. The plurality of positioning pins pass through the through the plurality of through holes of the capacitor housing and the at least one PCBA and are connected to the housing.

The invention discloses a VSG adaptive control method, which comprises the following steps: establishing an inverter model based on VSG control, introducing a virtual rotational inertia J and a damping coefficient D into the inverter model, introducing an SG2-order rotor motion equation to simulate the rotational inertia and realize primary frequency modulation characteristics, and deducing a control equation; establishing a VSG active-frequency loop small signal model, and introducing a transfer function of reference power-frequency and output power reference power to determine a variation range corresponding to the virtual inertia J and the damping coefficient D; and designing a fuzzy controller to dynamically adjust the virtual inertia J and the damping coefficient D in a variation range corresponding to the virtual inertia J and the damping coefficient D so as to realize real-time adjustment of the virtual inertia J and the damping coefficient D. According to the VSG adaptive control method, parameter adjustment is more sensitive in the face of small errors, and the selection range of J and D can be fully utilized and adjusted in real time.

The invention discloses an autonomous voltage support method and device for a network-constructed converter and a medium, and the method comprises the steps: constructing a converter network-constructed control topological structure, determining a droop control output frequency and a droop control output voltage amplitude according to the topological structure, obtaining the resistance and inductance of a power grid, and the voltage and current of a PCC point, and carrying out the control of the droop control output frequency and the droop control output voltage amplitude. The droop control output frequency and the droop control output voltage amplitude are combined to obtain droop control positive and negative sequence active / reactive reference power, so that an autonomous voltage support strategy is generated to carry out coordinated adjustment of a voltage outer loop / current inner loop, and the real-time impedance measurement is combined with reference power calculation based on autonomous voltage support to obtain the real-time impedance of the droop control output frequency and the droop control output voltage amplitude. According to the invention, accurate voltage support and power adjustment of the grid-forming converter in the weak power grid can be realized, the correctness of the support method is improved, the support capability of the grid-forming converter can be obviously improved, and the power quality and the power supply reliability of the grid-forming converter in the weak power grid with low short circuit ratio and high impedance can be improved.

The invention discloses a phase jump fault recovery method and system for a network-building type inverter, and the method comprises the steps: giving a-q-axis current component of a current loop reference value of the network-building type inverter as an allowable maximum current value in response to a phase jump fault of a power grid and triggering a current amplitude limiting request of the network-building type inverter, forming an amplitude limiting current loop reference value and limiting the amplitude of the output current of the grid-forming inverter; after the current amplitude limiting is relieved, the active power of the grid-forming type inverter is updated, a current loop reference value of the grid-forming type inverter is updated through the updated active power, and the current loop reference value is the current loop reference value obtained after the current amplitude limiting of the amplitude limiting current loop reference value is relieved; and under the condition that the current loop reference value is smaller than a preset current threshold value, the power grid is switched into a grid construction control state, so that the transient stability of the system is enhanced, the system can return to the balance point autonomously, and the grid construction operation state is recovered.

The invention relates to the technical field of inverter control, and provides an MBD-based reinforcement learning inverter control algorithm optimization method, which comprises the steps of S1, establishing a state space model of an inverter, designing a baseline controller of double-loop control, and constructing an MBD simulation platform containing multiple load models; s2, defining a state space of the 12-dimensional state vector, designing a continuous action space, and constructing an adaptive multi-target reward function; s3, training a control parameter optimization strategy by adopting an Actor-Critic algorithm architecture in combination with an experience playback mechanism and a hybrid exploration strategy; s4, establishing a security constraint mechanism of three-layer security protection, designing a fault detection and isolation strategy, realizing a closed-loop online learning strategy of pre-training-transfer learning-online fine tuning, and meanwhile, adopting a self-adaptive updating mechanism; and S5, verifying the optimization effect of the control algorithm through quantitative index evaluation, an experimental verification scheme and a real-time performance requirement test. And the upgrade of inverter control from model driving to data and model cooperative driving is realized.

In a cell-multiplexed inverter in which multiple cells are multiplexed and connected in a star connection to each phase of an AC system, even if an unbalanced AC voltage occurs or an unbalanced AC voltage is intentionally output, this eliminates the need to input a cell to the relevant phase or to raise the cell DC voltage only for the relevant phase, and also suppresses common-mode current. Phase voltage detection signal v U ,v V ,v W or voltage command value v U *,v V *,v W * is converted to a value on a rotating coordinate system synchronized with the grid frequency and a value on a rotating coordinate system rotating in the opposite direction to the grid frequency, and the DC component is extracted. 1d , Positive phase q-axis component V 1q , out-of-phase d-axis component V 2d , reverse phase q-axis component V 2q Based on the zero-phase voltage d-axis component V 0d , the zero-phase voltage q-axis component V 0q Calculate the zero-phase voltage d-axis component V 0d , zero-phase voltage q-axis component V 0q is multiplied by a cosine wave and a sine wave and added to obtain the voltage command value v U *,v V *,v W * to obtain the corrected voltage command value v U *',v V *',v W *'.

A zero-voltage switching ARCP-based converter that is capable of balancing its DC-link capacitor voltages and a method of balancing the voltages of the DC-link capacitors of an ARCP-based converter are disclosed herein. Each phase of the converter comprises a main section, an auxiliary section, and a control section. Main switches of the main section synthesize one or more reference voltage at the output of the phase. The auxiliary section facilitates zero voltage switching of the main switches. The control section provides gate signals for the main switches and the auxiliary switches based on the feedback signals from the converter to control the main and the auxiliary circuits. The method balances the voltages of the DC-link capacitor by utilizing ARCP-based hardware. The disclosed method minimizes switching losses and other EMI problems experienced by other converters.

The invention discloses a micro-grid power control method, system and device based on fuzzy modulation and a storage medium, and relates to the technical field of intelligent grid integration of a photovoltaic system and a micro-grid, and the method comprises the steps: firstly obtaining the real-time power data of a photovoltaic system, carrying out the control processing through fuzzy logic, and calculating a reference instruction; according to the reference instruction, hysteresis time is dynamically adjusted through modulation hysteresis control, and an inverter switching signal is generated; converting direct current into alternating current based on the switching signal and a power switching device, injecting the alternating current into the micro-grid, calculating active and reactive power reference values, ensuring that the system operates according to a unit power factor, and giving active power to the reference value; according to the method, the power control precision and adaptability of the micro-grid are improved, excessive switching of the inverter is avoided, loss is reduced, the service life is prolonged, power matching and stable transmission are achieved, reactive loss is reduced, bus voltage is stabilized, harmonic waves can be reduced, the electric energy quality is improved, and efficient and stable operation of the micro-grid is guaranteed.

The invention discloses an energy router inversion grid-connected port control method for optimizing a VSG, and the LADRC can dynamically compensate the influence of external disturbance on a system through the real-time observation of the state of the system, especially the monitoring of the disturbance and the change of the system, thereby enhancing the anti-interference capability of the system. When the load is suddenly changed or is externally disturbed, the LADRC can quickly identify the disturbance and generate an adaptive control signal, so that the inverter system is quickly recovered to a stable state. And the fuzzy adaptive PI controller adaptively adjusts the proportionality coefficient and the integral coefficient of the PI controller according to the real-time deviation and the change rate of the system, so that the parameters of the controller can be automatically adjusted according to the state of the system, and the limitation of a fixed parameter controller under complex working conditions is avoided. The self-adaptive adjustment not only improves the control precision, but also greatly improves the dynamic response speed of the system, so that the inverter can maintain an efficient and stable working state under the conditions of power grid disturbance, load change and the like.

The invention discloses a converter collaborative current limiting method based on adaptive virtual impedance and a power loop, and the method comprises the steps: firstly building an equivalent impedance model of a converter and a power grid, analyzing the steady-state and transient characteristics of fault current, and extracting key parameters for current limiting design; when it is detected that the voltage drop of the grid-connected point exceeds a threshold value, a self-adaptive virtual impedance link is automatically put into use, and virtual resistance and reactance values are dynamically calculated according to the variation amplitude of voltage or current, so that the virtual resistance and reactance values are proportionally adjusted along with the fault degree; and when the system voltage returns to normal, the virtual impedance automatically quits, and the control continuity is ensured. Then, the active and reactive power reference values are dynamically corrected according to the voltage drop depth, a power reference signal matched with the voltage amplitude is generated, it is guaranteed that power output does not exceed the limit, and the voltage supporting capacity is improved. Finally, real-time current-limiting control of the converter and stable operation of the system are realized on the premise of not switching the control mode through the synergistic effect of the virtual impedance ring and the power ring. The method has the advantages of being high in response speed, excellent in current limiting effect, good in control continuity and the like, and is suitable for fault current limiting and voltage support control of the grid-forming converter.

The invention discloses a grid-connected inverter control method based on second-order linear active disturbance rejection, and particularly relates to the field of grid-connected inverter control. Voltage and frequency error signals between the output side of the inverter and the power grid are obtained, a pre-synchronization control model is constructed, and voltage amplitude and frequency synchronization is achieved; a second-order linear active-disturbance-rejection controller is introduced in the frequency synchronization control process, an extended state observer is adopted to estimate the output frequency, the frequency change rate and a disturbance term, and a state error feedback control law is combined to generate a frequency regulation control quantity, so that accurate frequency control is realized; after grid connection, a dual-channel LADRC power regulation controller is constructed, and decoupling tracking control is carried out on active power and reactive power; meanwhile, on the basis of fast Fourier transform processing as a stable grid-connected state criterion, the method has the advantages of being high in control precision, high in anti-interference capability, good in current waveform quality, high in adaptability and the like, and is suitable for various grid-connected application scenes.

In a power conversion device that converts a DC voltage to an AC voltage by turning a semiconductor switching element (Q) on and off, a drive controller (10) that generates a gate signal for driving the semiconductor switching element (Q) on and off is configured to generate a first command which is a voltage command for a target voltage of the AC voltage, generate a triangular wave carrier signal whose frequency is an even multiple of a fundamental wave component of the first command, and generate the gate signal from the carrier signal and a second command composed of a harmonic signal including at least one odd-multiple harmonic signal whose frequency is an odd-multiple and one even-multiple harmonic signal whose frequency is an even multiple of the fundamental wave component of the first command, and the first command.

A vehicle battery module includes a battery, a first DC / DC converter, a second DC / DC converter, and an inverter. The vehicle battery system according to an example embodiment of the present disclosure includes a plurality of vehicle battery modules, and includes a first DC system output end in which first DC module output ends of the first DC / DC converter are connected in parallel to each other, a second DC system output end in which second DC module output ends of the second DC / DC converter are connected in series to each other, and an AC system output end configured in which AC module output ends of the inverter are connected in series to each other.

The invention provides a power grid connection disturbance observer feedback control method, which belongs to the technical field of power grid connection, and comprises the following steps: detecting power grid impedance parameters by using a multi-frequency harmonic injection technology, designing a disturbance observer algorithm to establish a state equation set, and constructing a nominal inverter model by using a low-pass filter; the total disturbance amount is estimated in real time by comparing the difference value between the actual current output and the nominal model output, a feedback control strategy is constructed, the disturbance estimation value serves as a feedforward compensation signal to be superposed to the current controller output, and disturbance components in different frequency ranges are processed in a classified mode according to disturbance types. A disturbance observer bandwidth parameter and a filter cut-off frequency are set, a disturbance estimation value is compensated to a current control loop in real time through a feedforward compensation signal to suppress the influence of power grid disturbance on the grid-connected current, and the technical problem that it is difficult to accurately estimate and compensate the influence of power grid disturbance on the grid-connected inverter in real time is solved.

The invention discloses a multi-level inverter hybrid modulation method and device, solves the current problems of limited number of cascade modules and unbalanced power of an asymmetric cascade multi-level inverter, and belongs to the technical field of cascade multi-level inverters. The invention is suitable for an asymmetric cascaded multilevel inverter topological structure. The topological structure comprises a single high-voltage module and (n-1) low-voltage modules which are cascaded together, the polarities of output voltages of all the cascade modules are non-different, and the high-voltage modules are modulated by adopting low-frequency step waves; and the low-voltage module adopts high-frequency carrier amplitude-shift modulation based on carrier displacement. According to the invention, the number of output levels of the inverter can be further increased, so that output voltage waveforms with higher quality can be obtained. When a low-voltage module follows a carrier replacement principle, all modules of the inverter can keep the ratio of output power to be k: 1: 1 in a full modulation range while the polarities of output voltages are non-different, so that the problems of power imbalance and power backward flow are well solved.

In an ACDC power supply, voltage balance of each DC bus is achieved when power is unbalanced without using an additional balancing circuit or a multi-winding commercial transformer. The ACDC power supply includes an AC-DC converter ACDC, a primary side DC capacitor C1, an isolated DC-DC converter DCDC, and a secondary side DC capacitor C2. Each phase has m cells (m: an integer of 2 or more). A DC bus V is connected in series or in parallel to a plurality of secondary side DC capacitors C2. dc21 , V dc22 Multiple DC buses V dc21 , V dc22 The voltage is supplied to the load or power source. When a power imbalance occurs due to the load or power source condition, the voltage is output while maintaining the voltage balance between the secondary DC voltage and the primary DC voltage of each cell.

The invention belongs to the technical field of power electronics of power supply or power distribution, and provides a control method of a three-phase four-wire inverter, a controller and an inversion control system. A first control component is generated by using a phase angle, an inversion side three-phase current sampling value and a proportional integral compensator; a second control component and a third control component are generated by using a power grid voltage angular frequency, a neutral line current sampling value, a repetitive controller and a proportional resonance controller, the three control components are combined to control an inverter power switch tube, a proportional integral compensator is still adopted, the algorithm is simple, parameters are easy to design, and the reliability is high. And meanwhile, a repetitive-proportional resonance (RC-PR) composite controller is utilized to realize suppression of neutral line fundamental wave and harmonic current, and the method has faster dynamic response to load abrupt change, so that optimization of dynamic performance and steady-state performance is realized.

The invention discloses a hybrid grid-connected power oscillation suppression method and system for a grid-forming inverter and a grid-following inverter, and the grid-following inverter controls the grid-connected power of the grid-following inverter through a current control type virtual synchronous generator. And the grid-building type inverter counteracts the interaction influence of the grid-building type inverter on the grid-building type inverter through the voltage control type virtual synchronous generator and double mutual damping control combining frequency mutual damping and power mutual damping, and the grid-connected power of the grid-building type inverter is controlled. According to the method, the power oscillation of the grid-forming and grid-following type inverter hybrid grid-connected system under the weak power grid and the strong power grid can be inhibited at the same time, the voltage and current harmonic waves of the grid-connected point are reduced, and the electric energy quality is improved.

In a cell-multiplexed inverter in which multiple cells are multiplexed and connected to each phase of an AC system using star wiring, the AC output voltages of the cells are made equal even when an unbalanced AC voltage occurs or when an unbalanced AC voltage is intentionally output. [Solution] A corrected voltage command value generating unit superimposes a sine wave of opposite phase to the certain phase as a zero-phase voltage on the voltage command value if the amplitude of the voltage command value of a certain phase is larger than the amplitude of the voltage command value of the other phase, and superimposes a sine wave of the same phase as the certain phase as a zero-phase voltage on the voltage command value if the amplitude of the voltage command value of a certain phase is smaller than the amplitude of the voltage command value of the other phase.

The power conversion device provided by the invention comprises a direct current end, a positive direct current bus, a negative direct current bus, a positive bus capacitor, a negative bus capacitor, at least three inverter bridge arms, a switch unit, a controller, filter inductors corresponding to the at least three inverter bridge arms one by one, a filter capacitor and an alternating current end. And the third end of each inverter bridge arm sequentially passes through the filter inductor, the filter capacitor and the switch unit corresponding to each inverter bridge arm and then is connected with the midpoint of the bus. The controller controls the switch unit to be switched off or the impedance of the switch unit to be increased when the voltage of the power grid is smaller than or equal to a first voltage threshold value; and after the switch unit is switched off or the impedance of the switch unit is increased, the modulation wave of each inverter bridge arm is controlled to be the modulation wave after the first common-mode modulation signal is superposed on the initial modulation wave of each inverter bridge arm, so that the amplitude of the modulation wave of each inverter bridge arm is increased. Furthermore, not only can the loss of the switching tube in each inverter bridge arm be balanced, but also the problem of common-mode oscillation caused by modulation wave change can be improved.

The present application relates to the technical field of micro inverters, and relates to a circuit topology of a micro inverter, and a control method. One specific implementation of the method comprises: measuring the maximum power value of a photovoltaic module, and receiving a current input by the photovoltaic module; acquiring a power grid voltage value in an alternating-current power grid, determining, on the basis of the power grid voltage value and the maximum power value of the photovoltaic module, a sine wave period corresponding to an output current, and on the basis of the sine wave period, controlling on and off of a plurality of switch transistors in a resonance circuit and a voltage doubling rectifying circuit in the micro inverter, so as to respectively form a conduction current loop in the resonance circuit and form an induction current loop in the voltage doubling rectifying circuit; and transmitting the sinusoidal output current to the alternating current power grid by means of the output end of the voltage doubling rectifying circuit. The implementation implements a control strategy for first-stage power conversion of the micro inverter, improves the efficiency of the micro inverter, increases the power of the micro inverter, and reduces the cost of the micro inverter.

A power module includes a first metal layer-coated substrate, a plurality of chips, and a first connection piece. A first electrode of each chip is electrically connected to a first metal layer of the first metal layer-coated substrate. The first connection piece includes a first main body part and a plurality of first contact parts. A second electrode of each of the plurality of chips is in contact with at least one of the first contact parts. A part of the first main body part is between at least one pair of adjacent first contact parts. A current flowing out from the chip directly flows to the first main body part through the first contact part. The chips are connected in parallel by using the first connection piece.