阅读说明：本技术 功率转换装置及使用了该功率转换装置的电动化车辆 (Power conversion device and electric vehicle using same ) 是由 市川贵文 家泽雅宏 和田典之 中野晃太郎 于 2020-04-10 设计创作，主要内容包括：现有技术存在以下缺点：需要设定与功率转换装置的电流指令单元的效率相对应的电流指令值,工序数变多。本发明的功率转换装置连接在三相交流旋转电机与直流电源之间,并将直流电转换成交流电,其基于效率指标来校正输入至功率转换装置的电流指令单元的直流电源的直流电压值,基于该校正后的直流电压值和转矩指令值来使电流指令单元所输出的电流指令值变化,从而对功率转换装置和三相交流旋转电机的效率进行控制。(The prior art has the following defects: the current command value corresponding to the efficiency of the current command unit of the power conversion device needs to be set, and the number of processes increases. The power conversion device of the present invention is connected between a three-phase ac rotating electrical machine and a dc power supply, and converts dc power into ac power, corrects a dc voltage value of the dc power supply input to a current command unit of the power conversion device based on an efficiency index, and changes a current command value output by the current command unit based on the corrected dc voltage value and a torque command value, thereby controlling the efficiency of the power conversion device and the three-phase ac rotating electrical machine.)

1. A kind of power conversion device is disclosed,

connect between three-phase AC rotating electrical machines and DC power supply, convert direct current to alternating current, its characterized in that includes:

a direct current voltage value acquisition unit that outputs a direct current voltage value of the direct current power supply as a 1 st direct current voltage value;

a DC voltage value correction unit that outputs a 2 nd DC voltage value based on the 1 st DC voltage value and an efficiency index;

a current command unit that outputs a current command value based on the 2 nd dc voltage value and a torque command value;

a current control unit that outputs a phase voltage command value based on the current command value and a phase current value of the three-phase ac rotating electrical machine; and

a voltage applying unit that converts direct current of the direct current power supply into alternating current based on the phase voltage command value and applies a voltage to the three-phase alternating current rotary electric machine.

2. The power conversion apparatus according to claim 1,

the direct-current voltage value correction unit includes: a 1 st calculation unit that outputs a voltage correction value based on the efficiency index; and

and a 2 nd calculation unit that outputs the 2 nd dc voltage value based on the 1 st dc voltage value and the voltage correction value.

3. The power conversion apparatus of claim 2,

the efficiency index is a signal of on or off, the voltage correction value is a fixed value, and the 1 st direct current voltage value is corrected based on the fixed value at the time of switching on or off.

4. The power conversion apparatus of claim 2,

the efficiency index is a command value indicating a system efficiency obtained by combining the power conversion device and the three-phase ac rotating electrical machine, and the 1 st computing unit outputs a voltage correction value corresponding to the command value.

5. The power conversion apparatus according to claim 2 or 3,

the 2 nd arithmetic unit includes a subtraction unit that outputs a difference between the 1 st dc voltage value and the voltage correction value.

6. The power conversion apparatus according to any one of claims 1 to 4, comprising:

a switching frequency calculation unit that outputs a switching frequency based on the efficiency index; and a boosting unit that boosts a direct-current voltage of the direct-current power supply according to the switching frequency and supplies the direct-current power to the voltage applying unit.

7. An automated vehicle, comprising:

the power conversion apparatus of any one of claims 1 to 5; and

and a drive wheel that is driven based on an output of the three-phase ac rotating electrical machine.

Technical Field

The present invention relates to a power conversion device and an electrically powered vehicle using the same.

Background

An electrically powered vehicle such as an electric vehicle or a hybrid vehicle is known, which uses a three-phase ac rotating electrical machine (hereinafter referred to as an ac motor) as a driving force source. In this motor-driven vehicle, the ac motor is operated with power to generate a running drive torque during running, and is operated with regeneration to generate a regenerative braking torque during braking.

Here, the drive system of the electric vehicle is configured by a dc power supply configured by a rechargeable battery such as a lithium ion battery, a power conversion device connected to the dc power supply, and an ac motor connected as a load to the power conversion device.

The power conversion device is composed of a capacitor, a plurality of semiconductor switches, and a control unit that controls the semiconductor switches. The plurality of semiconductor switches are turned on or off at a predetermined switching frequency, thereby converting the direct current of the direct current power supply into alternating current and adjusting the torque and the rotational speed of the alternating current motor. The ac motor operates as a generator according to an operating condition, and charges the dc power supply with regenerative power generated by power generation.

When the regenerative power from the ac motor is converted into a dc voltage by the power conversion device and used to charge the dc power supply, the ac motor may generate excessive power by generating power exceeding the power that can be received at the dc power supply side, and the regenerative power may become excessive, thereby generating an overvoltage inside the motor drive system. Therefore, it is necessary to suppress regenerative power to the dc power supply side by increasing the consumption of regenerative energy in the ac motor as necessary. In this case, it is known that a current command value having a high efficiency and a current command value having a low efficiency are set for the same torque command value, and a consuming operation for consuming surplus power is arbitrarily set (for example, see patent document 1).

Disclosure of Invention

Technical problem to be solved by the invention

In the power converter proposed in patent document 1, it is necessary to set a current command value corresponding to the efficiency to the current command means. In this case, the current command value at the time of high efficiency and the current command value at the time of low efficiency need to be set to the current command means based on the same torque command value, and there is a disadvantage in that: the number of steps increases, and setting takes time.

The purpose of the present application is to eliminate the need to set a current command value corresponding to the efficiency in advance for a current command means to suppress the number of steps, and to reduce the efficiency and increase the loss of a power conversion device and a three-phase ac rotating electrical machine.

Technical scheme for solving technical problem

Power conversion device disclosed in the present application

Connect between three-phase AC rotating electrical machines and DC power supply, convert the direct current to the alternating current, it includes:

a direct current voltage value acquisition unit that outputs a direct current voltage value of the direct current power supply as a 1 st direct current voltage value;

a DC voltage value correction unit that outputs a 2 nd DC voltage value based on the 1 st DC voltage value and the efficiency index;

a current command unit that outputs a current command value based on the 2 nd direct-current voltage value and the torque command value;

a current control unit that outputs a phase voltage command value based on the current command value and a phase current value of the three-phase alternating-current rotary electric machine; and

and a voltage application unit that converts direct current of the direct current power supply into alternating current based on the phase voltage command value and applies a voltage to the three-phase alternating current rotary electric machine.

Effects of the invention

According to the power conversion device disclosed in the present application, the current command value corresponding to the efficiency index is not set to the current command unit, and the current command value is changed based on the torque command value and the efficiency index, thereby controlling the efficiency of the power conversion device and the three-phase ac rotating electrical machine.

Drawings

Fig. 1 is a schematic configuration diagram of a power conversion device and a three-phase ac rotating electrical machine according to embodiment 1.

Fig. 2 is a schematic configuration diagram of the dc voltage value correction unit according to embodiment 1.

Fig. 3 is a schematic configuration diagram of the 2 nd arithmetic unit according to embodiment 1.

Fig. 4 is a hardware configuration diagram of the power conversion device according to embodiment 1.

Fig. 5 is a diagram for explaining transition of the current operating point on the iso-torque line based on the voltage limiting ellipse of the 1 st dc voltage value and the voltage limiting ellipse of the 2 nd dc voltage value according to embodiment 1.

Fig. 6 is a schematic configuration diagram of a power conversion device and a three-phase ac rotating electrical machine according to embodiment 2.

Fig. 7 is a schematic configuration diagram of the motorized vehicle according to embodiment 3.

Detailed Description

Preferred embodiments of the power conversion device according to the present invention will be described below with reference to the drawings. The same reference numerals are assigned to the same contents and corresponding portions, and detailed description thereof is omitted. In the following embodiments, the same reference numerals are given to the same components, and redundant description thereof is omitted.