38results about How to "Reduce circulating current" patented technology

The invention provides a multi-mode control method of an active clamp fly-back converter. In the fly-back converter, a controller realizes mode switching among a lagging edge non-complementary mode, aleading edge non-complementary mode and a leading edge non-complementary Burst mode of two driving signals after detecting a feedback voltage and comparing the feedback voltage with a set mode switching threshold voltage. According to the invention, the lagging edge non-complementary mode is adopted to reduce the circulating current of the converter, the leading edge non-complementary mode is adopted instead of a common fly-back mode to improve the light-load efficiency, and the leading edge non-complementary burst mode is adopted under the condition of no load in order to limit the magnitudeof the primary peak current in the burst mode, avoid audio noise and achieve low no-load power consumption.

Disclosed is a hybrid dc-dc converter. The hybrid dc-dc converter includes: a pair of transformers configured to magnetically couple a primary side to a secondary side, a full-bridge converter including four switches constituting a full-bridge inverter circuit and a first transformer, and an LLC resonant converter including a resonant inductor, a resonant capacitor, and a second transformer, which constitute an LLC resonant circuit, wherein an output of the full-bridge converter and an output of the LLC resonant converter are connected to each other in series at the secondary side.

Techniques for using multiple 18-pulse rectifier circuits in parallel are described herein. In particular, each rectifier circuit may include an autotransformer having 15 inductors coupled in series, joined by 15 nodes interposed between pairs of the inductors. The inductors may be represented as a hexagon in which alternating sides of the hexagon have two and three inductors, respectively. Each rectifier circuit may also include three inputs for three-phase AC power coupled to alternating vertices of the hexagonal representation and nine outputs for AC power coupled between each node that is not a vertex of the hexagonal representation and a respective diode bridge. Outputs of the diode bridges for the rectifier circuits may be coupled to a DC bus. In addition, a means for reducing circulating current between the parallel rectifier circuits and for promoting load sharing between the parallel rectifier circuits is also provided.

The invention discloses a track control method of a dual-transformer series resonance dual-active bridge DC-DC converter topology. This method first designs the control locus of the primary and secondary side shifting the phase angle outward and the secondary side shifting the phase angle inward. The high-voltage side voltage and the low-voltage side voltage of the converter are sampled through the sampling circuit. The digital control circuit is used to calculate the external phase angle of the primary and secondary sides and the internal phase angle of the secondary side of the current control variable. According to the control track, control the original secondary side external phase angle and the secondary side internal phase angle to always move along the track, so as to ensure soft switching conditions and minimum circulation control; output the control quantity through the drive circuit, and then control the operation of the converter . In this method, the closed-loop control follows the control trajectory based on fundamental wave analysis (FCA) by adjusting the phase shift angle and high-level duty cycle, which can greatly improve control flexibility, significantly reduce circulating current, improve efficiency, and ensure All soft switching is achieved over the full load range.

The embodiment of the invention discloses an intelligent load regulation circuit and control system, and is used for solving the technical problems in the prior art that when a balance between supply and demand is realized through electric power energy storage, electric power energy storage scale development is limited by economic cost and function bottlenecks, many higher harmonics are generated when a reactive compensator is adopted, the device size is relatively large and the cost is relatively high. The intelligent load regulation control system provided by the invention includes an intelligent load regulation circuit, three-phase non-key loads, three-phase key loads, a voltage controller, a central processing unit and a phase locked loop; the intelligent load regulation circuit is in series connection with the three-phase non-key loads to form an intelligent load, and the intelligent load is in parallel connection with the three-phase key loads; the input end of the phase locked loop is connected with a power distribution network A phase, and the output end of the phase locked loop is connected with the central processing unit; the input end of the voltage controller is connected with three phases of the power distribution network, and the output end of the voltage controller is connected with the central processing unit; and the output end of the central processing unit is connected with the intelligent load regulation circuit.

The invention discloses a non-master / slave self-current-sharing grid-connected parallel uninterrupted power supply system and a power supply method thereof, and belongs to the technical field of power electronics. The system mainly comprises two or more parallel same uninterrupted power supply system units, wherein each uninterrupted power supply system unit comprises four single-phase full-bridge converters (H1-H4), three industrial frequency inductors (LS, L1, L2), a high frequency inductor (L), a direct current filter capacitor (C1), an alternating current filter capacitor (C2), an isolation transformer (T), two bidirectional thyristors (K1 and K2), an air switch (B) and a storage battery (VB); the input side of each uninterrupted power supply system unit is connected with the power grid through the air switch (B); and various uninterrupted power supply system units pass through the second and third industrial frequency inductors (L1 and L2) and the alternating current filter capacitor (C2), are connected in parallel and are connected with the power grid through the two bidirectional thyristors (K1 and K2). The bidirectional energy flow between the uninterrupted power supply and the power grid can be achieved, the power supply system is a green load relative to the power grid, and the efficiency and dynamic response speed of a parallel system are improved.

The invention provides a motor (100) with a stator (40). The stator comprises multiple teeth (40T) divided into two or more sequence regions (A, B, C). A stator winding (90) comprises three phases connected in a triangular manner, and is wound to the teeth (40T). Each phase of the stator winding is equipped with two or more parallelly connected coil groups formed by serially connected coils ((1, 13, 7), (10, 4, 16), (2, 14, 8), (11, 5, 17), (12, 6, 18), (3, 15, 19)). The two or more coils ((1, 13, 7), (10, 4, 16), (2, 14, 8), (11, 5, 17), (12, 6, 18), (3, 15, 19)) are wound to two groups or more groups of teeth (40TS). At least one tooth from the two groups or more groups of the teeth (40TS) is selected from each sequence region of the two or more sequence regions (A, B, C).